Girls, ADVICE.

So me and my man have been together for 3 years. We have a one year old son. I’m 23 he’s 26. So from the jump I’ve always been an insecure person especially because he was married before me. He got married when he was 18 years old and divorced when he was 20. He says it was just a dumb decision he made and he regrets it because the relationship was just toxic. Anyways, so when me and him got together I had some trust issues due to past relationships so I was just insecure. It sucks. And then he had this old friend that he knew since he was 4 years old. Mind you this “friend” is a female. And I told him from the jump that I wouldn’t want him talking to other girls besides me or behind my back out of respect and he respected that. But anyways, when I had my baby, I suffered from really bad postpartum depression, I started getting a lot of anxiety and panic attacks as well. And then while I was pregnant I would check his phone and there would be times where I would see him looking up old girlfriends on Instagram and even would look up like his ex’s or old friends and I would confront him about it and we’ve had serious talks about it and he said he was just curious and that it didn’t mean anything. And TO THIS DAY, I have never found out that he’s cheating on me or anything or talking to other girls. I would always check his phone while he was sleeping and never found anything and to this day nothings come up. So I don’t think he would cheat or anything but the fact that he would look other girls up and look at their pictures would just make me feel so insecure and I’ve told him about it and he’s apologized and I haven’t seen him do it again. I don’t even check his phone anymore but I’ll use it from time to time because I have access to it. So I feel like I overthink ALOT a lot of the time I think like what would happen if I died or we split up like would he go back to talking to the girls he stopped talking to because of me ? Would he go talk to the girls he would look up on Instagram behind my back. Like my biggest fear is like one of those girls raising my son or shit like that. I know (call me crazy) but I just overthink a lot and ir sucks. I hate the way I think. Can any of you give me advice please? As a friend. I don’t like talking about this to anyone. I know some of you guys will be rude or whatever or judge me but it fucking sucks. He’s such a great dad , he’s a great partner to me, my family LOVES him. I’m not sure if I’m the one that’s just thinking the worst.