Looking for advise on how to let go of insecurities and fix my marriage

Long story long, my SO have been together since we were kids. We separated for a good amount of time due to infidelity on his end over a decade ago. The infidelity was with a coworker, I essentially knew before I knew. I could feel it, he was distant and all sorts of obvious about it. This led to about a year separation. Once we got back together he was much different to me, much better and eventually I trusted him somewhat. I have looked though his phone many times, at times obsessively, never finding anything. Fast forward to present time, he has a coworker (he is no longer in the same line of work as before) who is a friend. He was deleting fb messaging conversation. I confronted him about it and obviously that was a massive blow out fight. After a day or 2 we talked about it. According to him he deleted them because he didn’t want me to think something was going on because of his past. They work together often, he said she is just a cool person and there is zero attraction… He said that I dug and dug and dug for years and he just got to the point where he couldn’t do anything right, so he just kind of gave up.
A few weeks later there was a get together with a few of his coworkers, I got there later than him due to work and he was chatty with everyone but of course I focused in on every detail with the one specific coworker. This was my 1st time meeting the majority of them and I was a complete jerk to my SO, he tried to get me to sit with him, go inside, ect. I refused and was pretty distant and rude to him. He had been drinking and once we left, shit really hit the fan. Another huge blow out fight. That he just wanted to mak÷ me feel better and meet his coworkers and it was a disaster. I feel awful about it really, I feel like I pushed and pushed and pushed and now we are here. Prior to this we were the best we have been in a long time. A day after the fight he said maybe his past mistakes were to much and he doesn’t want to live like that. Which I can’t blame him for, im going insane. We have talked since but not really about anything to fix this. I send novel long messages but don’t get much if anything back at all. He is working nights right now so its extra tough to have a real conversation.
I know I have to work through these insecurities and become stronger. But I also need to know what he is thinking and where he stands and he’s not giving me much. It’s like he is forcing himself to try and show me a minuet amout of affection. This fight happend Monday and he’s been working since Wed. He works long hours so when he is home he sleeps. Im just lost, I don’t know how I can fix this. I am worried I am going to start to put up a defense wall and this will never get resolved.

Overall he is a pretty honest guy, not really a sugarcoat kind of guy. Typically if he doesn’t want to do something he will speak up. So I asked him of he still wanted to go on our trip, that I know things are shaky and if he wants to wait to see. He responded, were going. And thats it. I just feel like he is trying to force himself but that is also kind of out of his personality type. I really just want him to talk to me about all of this but nothing that I say really provokes anything.

Well if he said you’re going on your trip then that’s good. You said he’s normally someone who will say no if he doesn’t want to do something. I really think it just comes down to communication. You really need to sit down and talk about it. He obviously understands where your coming from but you need to hear from him that it’s nothing. He needs to back that up with actions, tell him by deleting those messages what does he except you to think. You also need to do healthy things to move on. You chose to get back together with him, I know it’s very hard but you have to trust that’s it’s different this time. If he lets you go through his phone & also takes you with him to go hangout with coworkers then that’s good… he’s trying to help you in a way you need to move past it