<human>: Condense the text into a few key points

So my bf and I live together, been dating for quite a while (years). I know he has friends outside of me, but the thing is, I know all of the ones he regularly hangs out with because they usually end up crashing at our place after going out. 

Tonight, I was browsing through Snapchat and found that my bf's "best friends" on there were me, rando chick one and rando chick two. After some research, I found he's Facebook friends with them and they live in the area. I've also seen him hiding his phone while he's texting and caught glimpses of female names on his phone. (Not snooping, just whenever it comes into my line of sight.) 

I know I have no reason to not trust him, but I also know that if he found me talking to guys he didn't know, he would be pretty mad. I've brought up the issue before, but I'm really bad at putting my feelings into words and I just end up being frustrated and crying which makes him frustrated too since he can't fix what's wrong. 

I feel sick, mad at myself, just mad at everything. I want to talk to him like a normal person would, but I just don't know where to start. 

Thank you, Reddit. Sorry if this was a bit scattered, please ask questions if I'm not clear enough. =]
<bot>: Bf is texting/snapchatting girls I do not know. I know if it were me doing so he would be angry. I just don't know how to say how I feel without making him feel accused.