Most of the time if your plan doesn't mention a deductible it will have an "out of pocket maximum". That is usually maybe $1500-$2000. There is bad insurance out there but chances are good that you have some cap on what you'd have to pay. As suggested, call your insurance company and ask questions about deductible, out of pocket max, coverage of hospitalization, etc. until you really understand.

My hospital gives a year to pay in theory but it really gives longer than that based on how they do the billing. If you meet certain requirements you can get financing with 0% interest and a longer payment term.

You can apply for a forbearance any time you have undue financial stress. If you can keep paying your interest then it just adds repayment time. If you don't pay interest it is added back on at the end. I used it a number of times when I was on disability. You don't have to give specifics, just check a box that says something about medical as the cause and it will auto-approve eventually.