Trying to fix my credit, now I"m on perm. disab. & my 05 car needs a motor. What can I do?

I live in upstate NY. I've been trying to rebuild my credit (it went bad after my child ped away). I bought an 05 car 3 years ago that turned out to be a money pit. I was trying to get ahead of the repairs & couldn't. Now the motor is shot, (it still needs other more minor repairs also) I can't afford the $2000 for a motor and I've been taken out of work on permanent disability (MS). I would like to have Chase Auto Finance just pick it up and make arrangements with them to make payments for what I will owe them when it's all done, but that will be a LOT and it will still go on my credit as a repo and kill what work I have done on trying to fix my credit. I don't know what to do. Any advice?