Please help

We’ve been through things because of him , like him going on POF ( dating website ) multiple times talking to women , him disrespecting me saying what he’ll do to me ( cheating wise ) but for the last 2 days things were getting good because 3 days ago I caught him on POF & we talked and I felt like he was serious. So of course I no longer trust him , but last night I had class , & I get home I see “ text now “ on his phone.. texting a girl so I confront him & he says it’s for puppies... so I called she said it’s not about puppies so I sent out text because I felt like she was covering it... she then told me that since I that I’m fucking her men , she WILL. So I said things and then texted her. Btw this whole time he is still denying it. So then he said “ just block her “ I said I did & he got mad and called her and said “ stop texting that number okay “ right in my face .. so I was like that don’t even sound right .. so we get home and he was like to be real that’s someone I met up at the store. So I broke down crying because it’s like it’s ALWAYS SOMETHING NEW. How would you guys feel. Am I OVER RE-ACTING & at this point Idk what to do... 😌😢 I’ve accepted all of his kids (6) & I have 0!! I’m loyal to him , go out my way for him and has never cheated or texted another guy