How would you feel in this situation?

I'm trying to figure what's the best way to handle a situation like this, both emotionally and with my boyfriend. It's happened a few times before where I find saved pictures of other women, some that we know personally and some that are strangers, on my boyfriends computer or phone. He uses those pictures while jerking off. It's been happening for a while now that I find those pictures, sometimes I fall upon them and sometimes I look for them. I would say that the first time I found pictures of other women was about a year ago and the most recent time was a week ago.

My dilemma is that I have no idea how to feel about it. When I see the pictures of other women on his phone or computer, I feel worthless, I feel like I'm not good enough. however I know he's not the only guy that gets pleasure from looking at/watching porn, heck, I know basically all guys do.

And don't get me wrong, I don't think that what he's doing is wrong in any way, it just makes me feel like shit. That's why I'm conflicted, I feel crappy about it but I know it's normal and not crazy for a guy his age.

I've told him how it makes me feel, but that hasn't changed anything, considering I still find pictures.

Has anyone been in a similar situation? I don't know what to do.

Update:

Not much of an update but I wanted to also mention that I do send him sexy pictures and urge him to ask me for some when in need. So I don't mind sending pictures, and he tells me he uses them but deep down something tells me he doesn't use those pictures and says he does to make me feel better.

We've also talked about this extensively and every time I find pictures, he's so torn about it, he feels sad that he hurt me and embarrassed. But I keep finding pictures...??