Is it cheating?

Found out my husband has been on many porn sites. Some have live Web cams and some are chat rooms and chat to girl websites.. Also some threads of men sharing different naked women pix they have managed to save he has been checking out. Also went looking for naked pix of his ex on some website.

About 6 weeks ago I found out he was chatting to a girl on snapchat (says he didn't know her and only chatted to her once) but she sent naked pictures and he never told her he was married just complimented her pictures :-( we were trying to get past this and now he's gone on all these other websites/chatrooms after agreeing it was wrong...

I would like to add that we have sex 2-3 times a week and he says he's happy with this so I'm confused and don't know what to do.

I'm so sad and low...