Relationship advice

Hey I just wanted an input in a relationship I am in. For starters I’ve been with my boyfriend almost 7 years and he’s done stuff in the past that has left me questioning if I should stay or go. This past year he has been texting girls from work and I was completely fine because it was mostly all work related until one day it was almost midnight and one of his coworkers texted him saying that she was feeling sad and it raised red flags because I never saw any conversation where they talked about they’re feelings mostly stuff about work or sending each other tiktoks so I got upset and was asking why was she texting him almost in the middle of the night saying she’s sad and he wouldn’t give me a straight up answer so he leaves my house and explains how the girl has been going through a tough and almost abusive relationship with whom she’s with right now and guessed she needed to talk to someone and I felt bad and told him I’m sorry and that he should talk to her if he wants he goes on and says I’ll just figure out what’s wrong with her tomorrow because it’s late. Whatever a day or two go by and he stays over and I go through his phone just to see text messages between both of them and her saying I’m sorry I didn’t pick up your call so I go over to his recent phone calls in which he deleted the phone call. I was enraged not only did he call her as soon as he left my house he lied to me and was deleting phone call from his phone. Am I crazy or is this much more than what I think it is? Idk I just need a friend for advice and I feel like I can’t really rely on anybody right now.