You are legally in the U.S; hence, you cannot be deported. If you have got a green card for ten years it means that you will be a legal and undisturbed citizen for the next ten years even if you are divorced. Make sure that you work on being a permanent resident within the ten year period.
You are already a U.S. citizen so need not worry, but before getting divorce get all the papers the legal documents in your possession and may land in trouble, may be for some time but there is a possibility it can happen from your husband side. So be careful ALL LEGAL DOCUMENTS LIKE PASSPORT CREDIT CARDS, AND DRIVING LICENCE. etc.