Quitting

This is my first post on this forum which I have been following from the side lines for some time now. I even bought Melissa's book on ADHD and marriage. I have been with my partner for almost 4 years now. He grew up in an orphanage where he was emotionally and sexually abused as a child. Has been a heroine addict, then an alcoholic. When we met, he was on his way to rehab. I have tried every which way to help and assist this man, and it has not all be futile. He was diagnosed as having ADHD early 2016 and started on Concerta. There has been some improvement but it hasn't been marked, mainly as it has not been accompanied by any therapy as he doesn't believe he needs any. He has also still been taking buprenorphine which he had been prescribed in rehab in an effort to treat his alcoholism by treating his past addiction to heroine. Needless to stay he became addicted to this. In addition his psychiatrist at that time kept increasing the doses so that he was at a whopping 12 mgs per day. he manged to wean himself down to 2 mgs per day, but told me and the ADHD psychiatrist he had stopped. I discovered the other day he hadn't. These 4 years have simply taken a massive toll on me: the constant mess (both physical and emotional), the emotional outbursts, the impulsivity, the selfishness, the emotional abuse. Not to mention two totalled cars, stealing from my bank accounts, my purse. The constant lies. I feel I have let a monster in to my life. I am deeply unhappy and have nothing more left to give. I started out this relationship as a strong, independent woman, but these days I have no idea who I am. I feel so ashamed that I have ended up in this toxic relationship. I have asked him to leave (not the first time), but as per the usual he throws massive temper tantrums in an effort to make me back down. But this time I won't. I want my life back. I want to be able to look myself in the eyes again, to look other people in the eyes again. Just this evening I was called a cunt for letting the dogs out when he asked me to let the dogs out. They ate the cat food he had left out. He raged about this for a good 5 minutes. I am unable to love this man.