Advice?

Tonight I was making dinner, it was about ready so I went to the living room to get my SO. As I was walking in, he was coming out with his phone in his hand, he said he needed to take this call. I said without really thinking it was a big deal "oh who is it?" He said it didnt matter and went into our room and shut the door. Honestly , our son and I just moved back in with him. Things were rocky and got bad so we left, he wanted us back and promised to be better blah blah blah the same old story and I believed him. I cant get this horrible feeling out of my head. Every time I look at him I wonder who he's cheating on me with. Crazy. I know. It's the worst feeling but I cant shake it. He never has actually cheated. He did message another woman once telling her how gorgeous she was, she sent the screenshots of what he sent her. I should trust him, I came back. Wasnt forced to. It's just that I'm working on trusting him. He'll go somewhere and tell me it doesnt matter where he's going, He's been in the room for about an hour on the phone with whoever it is. I honestly dont know how to approach this? Do I even ? Or is it really just none of my business? Maybe I'm overreacting. He promised me things would change this time, he knew it was time to grow up. We have a 10 month old son and another on the way. I was holding him, while I was finishing dinner after he left to the room for the phone call. And I was just thinking to myself. Am I really happy here? I couldnt actually tell myself yes. We have great times together, and we have bad times together but that's normal for couples right? I just thought. This isnt worth it. I constantly feel paranoid about who hes with or where hes at, who hes talking to . Theres been so much lying on his side over the years and if we dont have trust then what am I doing here?

Edit: As I'm typing this, he came out. I asked again who it was and he told me someone was calling him back about a loan. I said alright sure. (Not the best choice of words I'll be honest) he called me a stupid bitch and said look and shoved his phone in my face and held my wrist when I tried to move. I really feel like it's my fault. He stormed out of the house calling me stupid, took the keys so idk where hes going. He yelled at me in front of our son and has been since he was little. I cant let him grow up thinking this Is normal. Hes never quiet about anything, especially calling me those names in front of him. I know hes too little to get it right now but it's not this one time its multiple times. I need advice. I have nobody to talk to, and I feel like it's not all his fault, but I'm exhausted in this relationship.