Am I overreacting

Me and my partner have had trouble through out our relationship. He's lied to me, he's treated me unfairly and acted childish instead of trying to fix things, back in July I had our son and I bought my partner a bracelet so I went onto his email and found a "saved email" and in that email were pictures and videos of the woman he used to have sex with and mess around with (this woman was in a relationship too) apparently they were old photos but we argued and I was going to leave him. Fast forward to the past few weeks it's now November and I'm still not over it, every time he leaves the house I panic and everytime he comes home late I panic, I gave him a clean slate and I wanted to trust him but in the back of my mind I just feel he's being unfaithful. So today he never usually works on a Sunday but he's gone out today and I was mad because it's not paid work and it's just him helping out a friend who's working on a family members roof and I was upset because I don't see him during the week to spend time with but Sundays we usually spend time in our pyjamas and watch movies and cuddle with our little boy am I overreacting? I know I sound like a nag of a wife but trust to me is a huge thing and I'm afraid he's going to break the little bit of trust he's got left.

Thank you to the ladies who've commented on this post, I want to add that he begged me not to leave, he wanted me to stay and said he'd be a better partner and I trusted him. Even during the pregnancy I found things on his phone like Reddit images and stuff like that but I never thought he would stoop so low that he would bring up photos of a person he used to have a sexual relationship with and hide them from me. He's now "working" but I've tried calling and texting but no answer phone goes to voicemail I am considering leaving I've already got a place to stay if need be thank you for your comments 🙂