There's a lot of good advice here, of course it will be difficult to walk away he's been a part of your life for pretty much all of your adult life so far but honestly it will only get worse much worse and it's no life for you to live whilst he basically carries on regardless.
I say that because I was him - no matter what it wasn't a problem until it became a problem and I could see it for myself - I met my wife at 20 we both turned 45 in the summer - I've put her through hell due to my problems with drink and drugs but I honestly couldn't see it and didn't accept it was a problem until 1 year ago - that's pretty much a life sentence !!!
Yes things are better now but there's alot of hurt still to mend and stuff that she really never deserved, she's a lovely girl and I made her life hell for so long, it's only because I eventually came to my senses and could see it was out of control, that doesn't happen for everyone and a quarter of a century of someone tormenting you with their behaviour of which they will never take responsibility for is far too much to ask of anyone - I thank my lucky stars that she did stay but could understand if she had left me on many occasions - it's no life to lead for anyone - do yourself a favour walk away now, you have your whole life in front of you.
I have a teenage daughter and if she met anyone like I was then I would tell her to run for the hills and never look back.
Luckily some of us do eventually make it out the other side but it really is not worth the gamble with your own future happiness.