AIO boyfriend not telling other women I exist?

Hi, so I’m in a relationship with 32 M and amongst other things, we have hit some rough times.

I recently found out that a woman he used to sleep with prior to us meeting had been messaging him late at night and he didn’t tell her he was in a relationship now. This came out with a series of other lies that he had told during the course of our relationship and I cannot move past it. Is this cheating? He has since blocked and deleted this woman but I find myself questioning a lot about our relationship.

I cannot just leave him, there’s a lot of complications. I just want to know if I’m overreacting to this situation or I’m justified in my feelings.