Boyfriend been sex chatting and has porn account.?

[Rapidd]

I found out a little bit ago that my boyfriend of over a year has a account on a porn website and he has posted pictures of himself on there pretty much throughout our entire relationship. I cant even begin to describe how much this bothers me. He knows i know because i asked him about it but it ended in a fight and i never got to say how it made me feel. I then discovered that he has been sex chatting on the website with other girls and commenting on their pictures saying things like "nice bod, wish i could get behind you, we could have some fun etc." What these girls are telling him is the same exact things i tell him (about how he looks). I dont understand why he has to do this and why he has to talk to other girls when im right here. This hurts me so bad, i really really need some advice. im lost.
I am so in love with him, no one has ever made me as happy as he has, and dont want to leave him, i just want him to some how find out how much this bothers me.