stay here!
Your divorce case will be an easy one if your hu*****and agrees with it -- just do what xin-li told you.
I feel pity for you and I also understand your concern. I think you should stay here. Here, at least you can afford the basic living costs and if you go back to China, I don't see how can you afford your daughter's college expenses in China (that would be a huge sum of money for you). not mention the horrible health care costs -- no one can be sure that he or she would never get sick!
I saw some middle-aged, divorce women in China and I know how difficult life is for them -- simply no future. So stay here. I don't know if you have a future, but at least you have basic things and don't need to worry about your and your daughter's health care in case one of you get sick.
Take care and good luck!