I’m guilty of accepting credit cards for no fee/no interest for a year on balance transfers....
That's fine, if you use it to your advantage. Pay off that debt. Don't charge anything over that year, unless it's on a different credit card that you pay off each month. The catch is if you add to the balance on the "free" card, they often charge interest on the new debts and anything you pay cuts into the 0% debt, not the interest-paying debt.
It might be a burden to do so, but pay off all your debt. Drive a car into the ground so you can purchase the next one cash. If it's at all possible, find a way to avoid expensive monthly housing. Trust me, life changes once you're debt-free.