Sounds like a horrible situation to be in, but it could be that once you file those returns you won't owe as much as the letters state.
You might benefit from using a tax professional - TurboTax isn't actually a tax preparer and it actually doesn't "do your taxes for you", it's just software that allows you to do them yourself. That's not always the best option for everyone.
I really do bet you won't owe as much as the letters state - so try looking on line for your city forms for those years (most city forms are fairly simple) and see if you can get the returns together to see what you really owe. Good luck!
