The coke changes them and they become selfish arseholes. The nice version of them disappears forever then they start blaming you for everything. I divorced my ex husband and have twoboys with him. I gave him an ultimatum me and the boys or drugs. He chose drugs. The only advice I can give you is to never do that because then when they walk your self esteem hits rock bottom and no amount of therapy will get you over the abandonment. If I was me three years ago I wish I had the courage to actually boot the arsehole out myself as then at least I would have some self respect. Thinking you can help them or change them is an illusion. If they seriously want to change then they will fight for you and will probably need some serious help from the higher power along the way. I had 8 years of the same shit, it doesn’t get better it gets worse. You will be gaslit to within an inch of your life until you think you are going crazy. Your boundaries are repeatedly crossed to the point that what you start tolerating is so far over the line you can’t even see the line any more. I’m sorry if this isn’t what you want to hear, I know I wouldn’t have listened either, it just makes me angry that good women like you are treated this way and I don’t want you to end up the same as me x