Approaching girls while in a relationship.

So I’m currently in a relationship. I have a 4 month year old been with this girl for 2 years and we can’t stop arguing. We fight everyday and we actually hit each other.

There hasn’t been a day where we haven’t argued in sacred of Leaving because I want to be a family with my son and I don’t want to miss out on him growing up.

Me and my girl haven’t had sex since the child has been born since she is scared. I don’t think we get on anymore.

She is also the only girl I’ve slept with so my regret is not sleeping with other women

However today on the way back from work I seen this beautiful blonde girl we kept giving eye contact to each other she stood right next to me and I was tempted to chat to her and stuff. In the moment I really wanted to get her number etc.

However that would be a dick move and I left it.

So I was wondering is it normal to have these thoughts? Is it normal to want other women I was listening to a podcast where he said we always think the grass is greener and we back bad mistakes.

I’m not sure I’f I should break up with her and how I would even do it?

I’m not sure if I’m sexually attracted to her anymore I’m not sure if it’s because we haven’t had sex for so long or what? I love her but I dont think I have feelings for her I don’t know what to do

Any advice would help.