Living with my cheating Ex

I’m not sure what to do.

My ex (34 yr old) cheated on me (29 yr old) with his “friend” and I didn’t realize it til a month after he broke up with me then purchased an engagement ring. I just graduated nursing school and haven’t been an RN but for a few months.

Currently I’m living with him and my son. I’m pretty much having to start all over with a child. We were together for almost 6 years. Mentally and emotionally im hurt and although the woman claim to be “innocent” they still seeing each and he goes over her house at night. I decided to move to another town about an hour away to be closer to work. Whether than moving all the way to Colorado Springs.

Am I wrong for moving an hour away with my son? I can’t stay in the same town. Lately he has been trying to be there more for our son but couldn’t do it when we were together. I don’t want to make it seem like im taking him away from his dad but I can’t co-parent like this while you see and sleep with someone you cheated on me with. Im miserable. My only therapy is the gym. He even takes my son to her house for dinner sometimes. I haven’t started dating because im just so traumatized. He is a narcissist when it comes to relationships.

He tried to convince me to stay living here saying it would be half of what I would pay on my own but i whether pay then to live like this. Knowing I have a finances I need to work through. I feel like it’s easier to convince a woman to date a man living with his family then convincing a man. Or maybe it’s just because she is 10 yr younger. Plus, Who would want to date me, the placemat.

Idk if he is convincing me for our son, cheaper living, no child support, or so he isn’t alone, or to keep me around as a placemat since I ruined his engagement plan and he has to win her (22yr old) back. Idk what to do. It sucks because here I am sad and crying and I didn’t do anything wrong, while they are out happy and claiming to be “in love.”