Complete shot to my self esteem

I find my boyfriend looking at girls on his phone of course I flip out. I'm being unreasonable and jealous he says. It's not wrong if he doesn't try to talk to her or get her number right? So he says. He says he still has the same feelings for me but he's still going to see girls and think they're attractive and that I'll probably see guys I think are attractive. Sure but I don't stare, look at guys on my phone, I'd much rather look at what's supposed to be mine.  Our sex life has been dead for a while because he's used to seeing me and it gets boring and nothing will really help that.