I can’t help you with your DH and his attitude only to say..Stop catering to him.  

You have three capable children in your home who can cook, clean and do their own laundry.  There is No reason they can’t help out.   Tell them they are responsible for their own laundry.  Give each of them turns at cleaning up after dinner.  Have your 18 run errands if she can drive. 

And again, stop catering to your DH.  Let him do his own laundry.   

Ive learned that you will only be treated how you allow someone to treat you.  Stop being a doormat and take control.  No one else will do it for you.

That's a hard situation because he's just not around and you can't just ignore the kid, it's not her fault her parents are useless.  You can help her learn to do her own laundry and cook simple meals, etc, but at 12, she still needs a fair amount of support.

What would happen if you got a job outside the home and weren't there to care for her? Would he just ignore her needs?  That way you could be out of the house and also save up money to get yourself out of this situation, as it doesn't sound like he intends to do anything differently.

It really sounds like you have been dumped with a lot of responsibility.  And.. I commend you for not taking it out on the poor girl who has been saddled with not ONE but TWO "neglectful" parents.  Yeah.. there are different shades of neglect.. but your husband abdicating his responsibitity onto you.. and not giving his own daughter any emotional support.. the poor kid must be really lost. 

Now, I know it's not going to fix the root of the problem but the kids living at your home are all old enough to be fairly self sufficient and are old enough to be doing chores to help keep the household moving forward.

The 2nd part is that you need to pry your DH away from his work long enough to have a serious talk about his daughter.  He needs to know that his daughter needs him.. needs to know he cares..he does that by taking care of her.  She might need some therapy.. shoot.. the three of you might benefit since it seems your DH has checked out of so many things.  You can't care more than her bio parents.. but in this case.. neither parent is doing anything and I understand you don't want to let the girl just drown.

He needs to MAKE time in his schedule for his child.  If it helps, set up a calendar with specific "appointments" to do things with her.. or to make dinner etc.  Now, that might mean he orders a takeout pizza because he didn't plan for tuesday's meal.. but if he doesn't arrange for a meal on his night.. I would pack the lot of the kids up and take them out to dinner using HIS credit card.. he can stay at home. lol.  He needs to hear that you feel undervalued and over-burdened.  He needs to hear that while you care about his daughter that the girl needs his time and attention.  If that means he takes a break in working and then works later or gets up earlier.. then that is the result. 

Again, Kudos to you for stepping up and not taking your frustration out towards the girl.

So you don’t have to spend time cleaning.  Make rules,  everybody does there own laundry, cooking and cleaning up  schedual.  DH can not work 12 hours a day, seven days a week and have his DD living with you.  Either he take care of his DD or she goes some place else. You have to disengage or you are going to lose your mind 

Time to apply the behavioral and financial thumb screws to this guy.  Outsource everything he refuses to do and he pays (Housekeeping, lawn care, etc...).  Start throwing away SD's and DH's messes.  Bag it and put it on the curb for pick up on trash day. Including their laundry.  If they salvage it in time, great. If not... tough shit.

Immediately push for liquidation of the property or get an attorney and put together a buy out plan for him to buy you out.

If he will not step up, man up and be  your equity life partner.... then kick he and his toxic spawn to the curb.

He doesn't like the mirror you hold up in front of his face regarding his parental failures.  That is why you need to keep that mirror in front of his face 24/7 until  he adjusts his behavior or caves on the property. No more telling you he will get better.

Any time he tries that crap you reply with the mirror. "Don't tell me. Show me!" and keep his ass bare on his failure to follow through.

Good luck.

Take care of you.

It's long past time for the young people in your home to start contributing. 18, 13 and 12 are all old enough to divy up some chores.  Your husband and you both work so they need to pitch in. They can do all the yard work, vaccuming, dishes, their own laundry, pet care (if you have them) etc.  Let them know what needs to be done and let them choose what they'd like to do and rotate the chores if they wish. I'd give them an allowance as well. If they are completly helpless and lazy start small and work up from there.  

My 22 and 16 yr old sons live with me full time and they do almost all of the household chores, it's taken some training but it's paid off.  My 12 yr old goes back and forth between his dad and I but he still has to do his part when he's here. I think of it as future husband/roomate training. Someone will thank me for these well trained young men in the future, for now we all benefit by living in a clean living space.  

Your problem is the feeling like a doormat because you are letting eveyone walk all over you  including your own kids. Everyone needs chores and understand it takes a whole household to run a household. I haven’t cleaned my stepsons bedroom, it smells of mould, he always washes his clothes with not enough water or soap meaning they are still dirty and smelly and stinking up the house that hubby has to tell him off. 

My almost 3 yr old helps me tidy up her toys putting it into their storage containers, she helps throw dirty laundry in the washing machine, helps hand me clean laundry to hang on the clothes line to dry, if my daughter can any adult or teenager has no excuse and shouldn’t use the “my parents split up and i’m incompetent ruse”

So from now on, if stepdaughters room is dirty, tell her she has 10 mins to clear up, if she refuses to, any electronics are confiscated from her room till she tidies up (including her mobile phone), if laundry needs to be done- tell her she has 5 mins to start the laundry and must hang clothes after the washing machine cycle has finished, if she refuses to, confiscate electronics.

i’d suggest you do a roster where everyday one kid does laundry, empty trash, sweep, mop and help prep dinner or veggies etc for dinner. Even your own kids get electronics confiscated

then when hubby tells you off why did you confiscate her stuff that isn’t fair, tell him you do the same to your bio kids. When hubby is tasked with doing something, tell him when it needs to be done by. If 2-3 hours before that time limit its still not done, remind him again, 30mins before still not done, tell him it must be done. If he doesn’t do it, you tell him firmly he must do what you asked and that he promised to do it and hasn’t and he won’t come to bed till he does it. Be firm hun, i know it sounds like you’re being harsh and this will ruin my marriage and relationship etc but he needs that wakeup call what a selfish prick he’s being. 

When my daughter was 8.5 months old i told hubby off that being pregnant with baby #2 and major vomiting, i couldn’t do much and he and his 20yr old son from ex just turned a blind eye. I am no ones maid so from now on i don’t care if its hubby or stepson, cat litter must be done, their biscuits and water, trash emptied, laundry if not done he must start a cycle, if clean laundry hasn’t been hung he does it. I was firm and reminded him at present i am the only person feeding my daughter, making her bottle, bathing her and changing nappies, that i simply couldn’t trust leaving her in hubbies care while i gave birth to our 2nd baby. That hit him real hard and its been 2 yrs that he has continued with clearing kitty litter, their biscuits and water and emptying trash

now when ss does dirty things like dump trash on kitchen floor or piles rubbish bin till overflowing and never empties it, his dad gets a pic of the problem and a stern firm message saying “deal with this now from your incompetent son”, within mins stepson gets a message or call from dad at work to fix the issue immediately. He always has an excuse for everything but his dad is firm that you do not do this any longer because it is lazy and stupid

i know stepson isn’t happy because i’m like a chore nazi but his bio mum neglected him and never nurtured him and he’s milking everyone for all its worth and in the real world, we get tough love. Its for his benefit and i feel no guilt over it