Guys advice please! Is my bf losing his attraction for me

My bf (24) and I (23) have been together for over 4 years. 1 year into our relationship we moved across the country together away from all of our family and friends to start a new positive chapter in our lives. (Both our families suck) last year I got pregnant and this past August I gave birth to our baby boy. (First kid for both of us) During my ENTIRE pregnancy we didn’t have sex or be intimate….. like at all. And that was not on my part, I would try all the time and he would not want to. His reasoning being because he felt weird being that I was pregnant which was weird to me but whatever. So I came to understand it and didnt bother trying anymore. Fast forward to now, I am almost 5 months postpartum and have been ready to be intimate since my 6 weeks postpartum were up lol. I have been actively trying everything, even just to pleasure him. And I am very vocal and transparent to how I feel. He still always turns me down or another thing he does is he will act like he wants to and rile me up just to lead me on and turn me down when it actually comes down to it. I’ve spoken to him about it multiple times trying to get an understanding and he always says it isn’t me it’s him but a couple weeks ago I caught him pleasuring himself in the bathroom to 🌽and when I spoke to him about it he admitted that he does it at least a few times a week. (Even on the days I try to be intimate and he turns me down) I also went through his phone because I was feeling insecure and found that he has been constantly liking girls half naked photos on social media. LIKE A LOT. And I know he isn’t actually cheating but I’m scared that that is what is next to come.

So my questions are he not attracted to me anymore? Do I have something to be worried about? And what should I do?

EDIT: First off thanks everyone for the advice to far!!!! And secondly I’d like to address some questions a lot of ppl are asking. 1. Yes, he wanted to be a father! I replied to a comment explaining further detail. But yes he wanted to be a dad and was very happy when I got pregnant. (Happier than me) 2. Obviously the elephant in the room is I just had a baby a few months ago so I’m not back at my normal weight yet. BUT I have been actively getting it off and I’m also not that big. I almost look exactly the same except for a small little pudge belly that is ALMOST gone 😊