Confused???? Currently In a relationship with my current boyfriend he's locked up bec: we had a domestic case.?

He's saying he wants to change, go to counseling do everything so he won't loose me as his girlfriend. Then all of a sudden my ex-boyfriend pop's up at my cousin house, looking for me he wants me back. So i go see him and i slipped up and had with him. Know i feel really guilty!!(let me remind you he had 2 kids that he never told me about, and cheated. and know basic. hes regretful what should i do in this situation???????