Why can't you go back and finish getting your medical degree?
Also, if the default from over sever years ago? If so, you need to find out if the loans are beyond the SOL, then you can decide if they can come sue you or not to collect. If the defaulted loans are beyond the SOL, maybe you don't have to worry about these.
However, student loans might not have a SOL. In which case, you'll have to ask for amnesty and see if you can make a settlement offer for like 30% of the original balance. yeah, that's $60,000, but it's better than $200K.
You can't think about getting that new car, if you owe a few times the value of the car to the government.
But it's all about SOL at this point.