Lovey

I feel really bad for you April. Is it the masturbation or the porn or the lying and sneaking that bothers you ? Is it that you just want more sex?
Have you approached him about watching it together? Or do you feel comfortable with that?

He's at that stage that he's not even tending to your needs. Have you ever had a big discussion with him about what you need and desire?
Let him know that you feel close to him with sex and that you would like it more often. Because the porn isn't inhancing your sexlife but detracting from it, It's making you now feel less of a woman and that's BS. That's going to breakdown the walls of communication.
My advice in all of this is not to let the communication lines down. Try not to make him feel bad about looking at porn, because that's not your intention. Your intention is to tell him how you feel and for him to understand it. Maybe your intentions are just to get more sex.

Your man is preferring the porn and masturbating to being with you - he's being selfish with sex. While once a week is fine for some, when it's not for you, I think that seeing someone would help get some of the emotions and issues out in the open.
The sneaking around is from the past. I've found that sometimes they feel like scumbags because they were taught that masturbation was wrong, so they feel a sense of shame doing it.

Don't let his looking at bigger breasts bother you. Big, small, they're all great. It is just a matter of getting his eye back on you and less on porn.