1. yes, you should have some options for 还债计划, talk to the credit card banks.
2. If you default your credit card debt, I don't know if they will 冻结银行帐户; but your credit score will suffer.
3. I think if you 申请破产, you don't need to 还债. Ask attorney?
If you are young and want to stay in US, I think you can work out the deal with your credit card company. Tell them you have no money, and if they don't want a deal, then you go default and they got nothing.
"我申请破产, 是否就不用还债了", yes. But IMHO, I won't go there. Very very sorry to hear this.
Unless you are not gonna to settle or work in US, file 破产 is a very very bad idea, when you look for job, a lot of employers will check your background, if you apply for a job in financial industry, it is even impossible.
Try to negotiate with the credit card company, it is not a lot of money, if it is $2 million, it will be a different story....