I had a long post typed out to you and my connection poofed out from the tablet at the other end of the house...must have been a fat cat body blocking the signal...I will place aluminum foil on everyone's tail to improve this, yes?
I think that you have had ENOUGH, you sound as though you are reaching that saturation point and self-preservation is kicking in....detaching from him is hard, but necessary, you are formulating an ACTION PLAN in your mind and paper will help, bringing in a strong male figure (who you have explained this to in depth that it is killing you) will help too.
Your son, KNOWING AND SEEING a change in mama will also stop him from manipulating you further. That you can do right away and easily, without stomping or drama, just a subtle change that lets him know you ain't kidding around....
If you cater to him with food or cigarettes, stop NOW. Eat what you want, buy what you like and do it when YOU want to.
one more suggestion, get outside today, go somewhere and do not give him any information about it. take charge.
we are here with you, I wish you lived closer, I would come and drag out the door to go walk Sammy.
I can never imagine Ann in her previous turmoil, yet I know she was there. She worked really hard to get to a good place and I think you can get there too. big hugs.