I just found out my "husband" was never divorced from his previous wife. How do I handle that? Are we considered married? Do I still need to divorce?

If your facts are correct, the answers are, too. Under Nevada law, if anyone attempts to marry, but has a prior spouse still living, the later marriage is "void ab initio" -- and automatically null and void. If the second "putative marriage" has been of any significant length, then there are property and debt (and, potentially, support) issues that can and should be addressed even though the marriage is invalid, and the invalidity of the marriage will have no effect on custody or support of any children. Some additional information is posted at http://willicklawgroup.com/annulment/, but if you need more detailed analysis or answers, then you should make an appointment with a family law specialist and ask them directly.  See http://willicklawgroup.com/consultation-policies/.