I don’t know what to do anymore.

So me and my bf have been dating for 4 years. (On and off). I’m currently 20 weeks pregnant and on sep 22nd we found out we are having a baby boy and he proposed to me at our gender reveal. I thought are relationship was at its peak but I finally found out his phone password and I just had a feeling something was going on so while he was upstairs I got on his phone and looked through the pictures on his camera roll, I found a picture of a girl I used to go to school with in her bikini that he had saved. The picture was from the weekend after sep 22nd. Literally a week after we get engaged!!! First off he didn’t even know I knew his password cz he never lets me on his phone and secondly I couldn’t even imagine what the rest of his phone looked like cz I saw that one picture and got off his phone. Ran to our room crying (we live together) he then was yelling for me and I texted him saying I saw ur camera roll. And that’s when he knew what he did. I honestly don’t know what to do we talked about it but I’m just hurt. We then took a vacation with his mom and sister and it was the worst time ever just bcz I didn’t even want to be around him plus all these girls walking around in bikinis and just me feeling like he was staring at all these girls. I feel so shitty about myself and I’m super depressed bcz of all this. What are your opinions. I just don’t know what I want anymore. This also is the second time I have found pictures of other girls on his phone and he does more with them obviously 🙄 but he also does u know what to the pictures when I’m sleeping in bed right next to him! 😢😡