Boyfriend won't let me touch his phone?

Me and my boyfriend have been arguing non stop constantly and it is driving us insane!!! We've been together for 2 and a half years so we're so used to each other and need more spicing up to connect more. However I came to grab his phone last week and he snatched it off me to which I felt offended and it caused an argument. We got over that and grew up and I explained how I want to feel like I can be comfortable and we trust each other. However tonight we got into another argument because I grabbed his phone and he literally dug his fingers into my hands and took it off me with full force!!!! What the hell is going on!!! He never used to be like this until recently (3 months ago or so) and his done it a couple of times recently. Since the first time his done it I told him the way it makes me feel so he should know by now to not do that. I confront him and he beats around the bush and says his hiding nothing, but his actions makes me feel like his guilty. If he had nothing to hide why can't I touch his phone? It makes me feel so insecure and all the "what ifs" are running through my head. Am I over reacting or would you girls feel the same? I just feel so hurt not knowing what else or who else is out there 😔 (honest answers please)

Update!!!

Girls I was NOT going through his phone to snoop! I wanted to USE his phone to which he buckled and that's when I began to question!!!