I think my boyfriend is cheating

I've been pretty I'll over the last 9 months and yesterday when my boyfriend was showing me something on his phone I saw the app for plenty of fish. I think he thought he shipped through it too quickly for my to see but I saw it!

I did the worse this and tried to get on the app when he wasn't in the room but the password wasn't in there but the username was.

I can't search for the username and I don't feel like I can confront him as I feel like it's my fault if he has lost interest.

What am I meant to do????

Is he cheating? Got bored?

We met on that app around 2 years ago and I would happily accept it if he had forgotten to delete it BUT he got a new phone so why is it there?

I set up a dummy profile to see if I could find the username but you can't search the username on there anymore.

I did however manage to find one of his friends who's in a committed relationship but doesn't look like it's active.

I'm driving myself insane