Hi.I am US citizen and I take Social security income plus food stamps.I am getting married to a guy who is in USA RIGHT now on B/2 visit visa.we are in love and want to stay together.can I sponsor him for green card so that we can live together?

Yes.

If you don't have enough income to sponsor him for the Affidavit of Support, you will need to find a joint sponsor.

Agree, it does not sound like you have enough income, so you will need someone else to help.