I hate being an adult

So the first post about the ex. The last tie I have with him is a car loan, I am first which means that as he stopped paying my credit tanked. The car was leased on this really cool program that would allow you to refinance the balloon amount and keep that car. 4 years ago when we bought the car that was what we were going to do. A year later we were done and the car drama started. He has done nothing about this car now that the lease is up accept whine that he wants to keep the car and ask me to co-sign another loan. Now why should I do that when he hasn't paid this one on time in over 2 years and I am not getting child support like I should, and I am not getting any help like I should and last b/c I am the one having to pay for my son's ortho work on my own. That is a lot of money. He is 7 but has already started down the braces route.
Back to the car, I am the one who has been doing the running around about it. In clearly states in our divorce papers that its his car but the loan people will not accept that so they have been harassing me. I am going to have to pay on the penalties which was supposed to go to paying off my debt. I am so mad!!! I was finally going to be getting back on my feet and then this crap happens. I know that I can't blame him entirely for the debt that I have but he didn't help me out when I was in school and working part time and raising our son so consequently I had to put a lot on my credit cards that shouldn't have been. I mean come on now. Why do I have to be the adult and deal with all of this? He is 7 years older than me, he should be dealing with it not me!!!!
So as I sit here waiting from a call from the dealership about when and where to drop off the car, I also have to figure out how to get it there b/c it was broken into a few months back and his lazy A$$ didn't get it fixed. Which by the way means more money that I am going to have to pay out of my pocket.
My mom did point out that this means I am completely free of him now. Ok that is a good thing but why do I have to pay to be rid of him? I paid for the divorce and he left me!! I lent him money b/c he was irresponsible, I am still helping him out when do I get to be done!!!
I hate being an adult.