We have no way of telling you your citizenship, or why any particular agency might believe you're a citizen. You'll need to figure that out yourself or work with somebody who is able to dig up records for you. If you're telling us you're not a citizen, perhaps you're being confused with somebody else. Your application for a SSN, from what you've told us, should have been rejected - perhaps you're being confused with somebody else with the same name.

If you aren't a citizen, you can attempt to adjust your status based upon your marriage to a citizen, but you'll have to deal with the issue of your history of unauthorized employment - and perhaps other issues as well. I suggest consulting an immigration lawyer.