Fiance Acting Up

I need help. PLEASE no judgement, I need advice and I’m really confused.

My fiancé has messenger. No big deal. But I noticed it says, “using messenger without Facebook,” When I opened his messenger and clicked on “profile,” it takes me straight to his fb profile. So that confused me. But the other situation tied to that is, his fb messenger icon would continue to indicate new messages even though he said he didn’t have the app. On top of this, he’d decide to download the app once in a while to check. Whenever I questioned him he’d say he didn’t know. Meanwhile he’s a tech guy who can build computers. I questioned him over “using messenger without Facebook,” he got upset, saying anyone can tie their messenger to an app like Instagram and others. He always told me he didn’t have Instagram. A month ago I found an Instagram where he’s following women who do fitness. We argued and now I actually want to break up. Too many questions that can’t be answered. He has access to my phone 24/7. I don’t. He leaves it open but he watches me when I’m on it. And I never go on it because I always have mine. The other night I saw him on messenger. He’s yelling and not listening to me saying he’s tired of the questions that he doesn’t need to go to lengths to show women he’s honest. I got up to use the bathroom and saw he was on the phone, and threw his phone down. He won’t answer that, instead talking over me accusing me of wanting out since I’m moving in a week. Saying I’m judging him by my exes. I admit I have trust issues. But I know this is weird to me.