You are not being unreasonable at all!  Your husband is totally out of touch - you have gone way above and beyond for your SD.  You do not need to allow her back in your life or home.  I sure wouldn't.  You have been incredibly patient!  

I'll be super blunt: your DH has failed as both a father and a husband, and he's currently useless as both. I'm not blaming him for his daughter's drug issues, but I am 100% blaming him for continuing to enable and coddle her.

My advice? Separate, at least physically. You can remain married but live in different homes, at least until you figure out what you want to do permanently. That not only physically protects you and your belongings, but gives you mental clarity for how to proceed. I would also advise filing for a legal separation in order to protect your assets.

Here becomes the second blunt part: you're just enabling him to keep enabling her by staying. I get not wanting to throw away 20 years, but at some point, you have to protect yourself. He isn't going to do it. He'll continue to let her in. Without you as a buffer, he'll either realize that he effed up or he'll double-down on "being there for her".

This relationship isn't healthy, and it's going to take you making a major shift to even give it a chance to try and be. You're not the reason it's unhealthy, and it's not your responsibility to keep bending and bending to make it all okay. Your DH's issues with his daughter are his to overcome, not yours to overlook.

For years I bent over backwards to over prove that I wasn't the mean old SM who was trying to "ship the SKs off the boarding school," as per the societal stereotype of the mean old SM. I was in agony during my marriage and finally realized that I was being unreasonable. To myself. I was going way overboard to prove that I was a supportive wife and SM that I was enabling a dynamic that hurt me. That was the day I changed. Yes, it shook things up a lot, but I had been in agony for way too long and no one seemed to give a shit. 

So, to answer your question on whether you are being unreasonable. Yes, you are. To yourself. You do not have to enable a dynamic that hurts you. You have every right to have requirements from your husband and to enforce them. You may have to spell out to your DH that he's going to have to compartmentalize his relationship with his DD, but that'll mean he can love her up all he wants away from your home. You have every right to expect that your DH will protect you in your home rather than require you to eat shit. Just be prepared for your DH to ramp things up to try to "whip you back into shape." Stay strong. Weather the storm. It'll get ugly and it'll be scary, but nothing changes if nothing changes. Since neither your SD nor DH will change, it'll have to start with you. Be healthy to yourself and don't feel one iota of guilt about it.

Please tell me that he hadn't already moved her in ... If he has, then that was the sneakiest crappiest thing he could have done and it's a betrayal of you and your marriage. His daughter should not be coming between you.

For goodness sake, the woman is FORTY! What self respecting woman runs home to daddy at that age. What is the excuse this time for her being there? Getting back on her feet? Tell him she should have been more careful not to fall over ...

IMO, if he wants to see her he can to it elsewhere. Your home should be your safe haven and yours cannot be with an interfering, trouble-making harpy setting up her web in it. Do not allow her to move in or you will never get rid of her. Remind your husband who he's married to (and it's not her). You're just back from seeing your son in his home, your husband can do the same with his daughter in hers.

Oh, also, another important thing to note - keep an eye on your bank accounts for any suspicious spending or withdrawals. 

Finally, if she does set foot in your home and if she steals the slightest object, call the cops and report it. 

This is easily a case where I would tell my DH.. if YOU want to see your daughter.. that's up to you.. I understand, but "I" am not interested and am done so you can visit and see her outside our home.. that's it.

the only reason I might waver on that is if your DH has issues that make it difficult for him to leave your home.. and if you were able to "give them space" in that type of situation.. but I'm guessing that is not the case here.

I have an SD23 Feral Forger who last september did this same thing via text. I will certainly not want to see/talk with her, we are no contact which is FINE with me. She doesnt drop by and I would not be happy with that if she did. Feral Forger also steals and does drugs and doesnt have a job or a license.

The thing is, these spawns will always be their children, they will ALWAYS have their emotional hooks in there, always. The hooks NEVER go away. They may flow in and out of their lives and only come in when they need want something. Feral Forger is the same. She doesnt text or call her father until she needs/wants something that she cannot get from someone else. Their relationship is very transactional.

It sounds like an extremely stressful 20 years with this Skid.

You are completely justified in drawing these lines called BOUNDARIES, and you must stand strong in them because there will be pushback from what it sounds like. JRI is another steptalker who it sounds like has the exact same SD and the exact same enablement. She separated finances. HER SD is 60's. They finance the SD in a separate apartment to keep the sanity.

Why does your DH need you to interact with SD?  Is it because he can’t handle the waste he helped create and enable on his own?  Is it because he doesn’t like being alone in the toxic dumpster fire that he helped perpetuate?  I’m curious why it bothers him that don’t want to interact with a drug addict? 

OP, I came back to share that I know a bit about addiction. Both my DH and I have relatives that are addicts, and have seen the destruction these people cause if we don't have strong boundaries. 

I've seen the damage addiction has caused to three generations of my DH's family. So you need to be prepared to let your H go if he can't or won't stop enabling his daughter. My FIL enabled my druggie SIL until the day he died. He left behind a middle - aged woman with no job, no skills, no education, and no ability to manage her own life. He never considered what life would be like for her when he wasn't around.

You need to get selfish and focus soley on saving yourself, because there's no guarantee your H will want to/be able to get healthy with you. If he follows you on the path to healing, great, but the only person you can save is yourself.

(((hugs))) That's one of the crappy things about dysfunction - some people will fight hard and dirty to stay in it. It would be NICE to get healthier together, but all we can do is work on ourselves. What are some things you can do while you're processing and getting stronger? Can you start putting together an exit strategy? Look into resources for families being affected by addiction? What about letting the marriage drift for a bit while you find a therapist? Someone just for you that can listen and equip you with some new tools?

Something else I learned through disengagement was that being nice was not working for me. I'd been too nice for too long, so everyone was shocked, then angry when I stopped. I stood up to my DH in ways I never had before, and surprisingly it was very effective. I guess he was so used to crazy and strife that it was a language he was comfortable with, so when I told him off and called him a p@ssy (not my finest moment), he shut up.  It took me eighteen years to learn that  my DH respects strength, and our marriage is better because he knows I have limits.