Co-signer questions!

Hello! I made an extremely poor decision 2 years ago to co-sign on a car for my ex fiancé with his sister.

He has been missing payments so often, even got it repossessed, got it back & then crashed it (ridiculous) & is now missing payments AGAIN.

I know there’s no way for me to get off of it, and there’s no way for me to pay the car note & take it from him (because legally his sister & I are both on the title) but is there ANYTHING I could possibly do to be rid of this nonsense and move on with my life without this guy ruining my credit & my future from his poor life decisions?
once again, I know I made a huge mistake, I don’t need to be told again & again. hindsight is 20/20 and I thought we were going to be married and live happily ever after, obviously I was wrong and I had to leave him but I just can’t believe there’s nothing I can do to fix this mess.

I have a car loan on my name for a brand new car meanwhile I’m driving a 2002, paying for an apartment on my own meanwhile this guy lives with his parents, no rent to be paying & is hurting both of us. I just am so fed up with it all.