Hello All-I need some support, help...etc.....

1 month before we were to be married (husband and myself)-his ex wife tells my then fiance that he can have their 15 year old Son. I have known my husband and his ex-wife and all 3 of their children for many years-even before their children were born. I wasn't the cause of their divorce-and dated my husband for 8 years prior to getting married.

So-my Fiance soon to be Husband brings his Son home-we are married one month later--and it has now been 3 years since we got married. SS has never had any responsibilities--doesn't put away own dishes, pick up own stuff, won't turn off lights etc. When I asked my husband about this--he said his mother used to yell and scream at him--let him adjust to being here with us and i hope that he will learn by example....like I said it has been 3 years. SS will graduate from high school in May--I am invisible in my own home--SS doesn't say hello to me--will walk in the room and get between DH and myself and begin talking--there is no schedule--DH is out everyday picking some kid up or doing some activity--I can't plan anything-DH will not change anything in the house--ex wifes stuff is still all over the house--I once moved the living room furniture around and you would have thought it was WWIII from the reactions--those people don't do well with any type of change. Thanksgiving I am expected to go to his mother's house for dinner with the kids-they do not even say hello--I am a Mother to 4 adult children--my kids have manners--they have never treated my husband poorly--it would not be tolerated. His children are 18, 16 and 14. I have a great deal of internal conflict going on--feel so stressed, and generally get teary eyed when I think about going home lately--I hate the environment there--I have made my husband aware of how I feel--he doesn't feel the same way so it doesn't bother him--he says he can't deal with conflict--I am basically supossed to be quiet, keep the peace, put on a happy face.......all the while i feel fake--I love my husband...but feel like i am always walking on eggshells, nothing is ever resolved......i'm to the point that i want to take a travel job (I am a RN) until SS leaves for college! I don't know how to change the environment in my own home....any advice will be appreciated!