is it worth it?

Ok so after 17 years....2 kids, abuse (drug, physicsl,emotional) nfidelity,2 mental breakdowns, a adhd son who is getting worse by the minute because of dads untreated adhd, childhood issues and dysfunctional family,,,,i have been asking myself lately.....is this worth it? I have been to hell and back on several occasions and i cant say for even a second any of it was worth it. For the exception of my kids nothing good has come out of this marriage...not one..why oh why did i do this? Why did i stay so long.? Why did i let things go so far....why did i expose my kids to this life? Its all my fault.....i thought i could fix it..i thought i could make it better....i made nothing better...i thought i was helping him ...but i just been his co dependant and he has taken my kindness for weakness and drained the life out of me,,,,im stuck in a marriage of no choice at this point, with a man who is a liability more than anything else.....cant count on him for anything, he is my 3rd kid and i hate him for it. He wants to change but he just doesnt know what to do,,,,,BULLSH*T.......adhd or not i feel everyonr can make s choice if they want better......im so bitter, resentful, hurt and just want to run and not look back.......i dont wish this on anyone......sorry for rambling but i really needed to vent...no one knows my true life i suffer in silence....