I am depressed because my boyfriend looks at pornography?

[Emma]

Back in October 2013, I was clearing my internet history on my shared laptop I share with my boyfriend when I came across these searches on Twitter for things like "dirty teens" and "teen selfshot". He was on pages with girls topless and naked for ages. This was when I was sleeping right beside him!?! Anyway, I felt very upset because my boyfriend has always been so loving and caring to me, and he has always came across as a guy that wouldn't be into that stuff - he was so innocent and I felt like only I mattered to him. So it came as a shock and I was very hurt and heartbroken. I confronted him and he admitted it, he said he is so sorry for hurting me, and he cried to me about it. He told me he had only looked at these things twice since being together.
Everyday since October it's all I've been thinking about. Feeling like I am not good enough because I don't have big breasts, or bleach blonde hair. I have spiralled into depression because my mind keeps repeating the titles of the pages he was looking at, and playing the images over and over in my mind. He was also on hundreds of girls photos that he actually knows on Facebook everyday.
Two nights ago, I was on his old laptop trying to fix it when I right clicked on the Google Chrome tab and it came up 'Most Visited Websites' and the top was a porn site. Obviously I was curious because he told me he had only looked at things twice since being together. I found out he was on it hundreds of times. I texted him asking him what was going on and why he had lied, and how many times he had actually been on it.. He said 'too many times and im sorry Emma'.. I selfharmed both my arms, and I tried to suffocate myself because I already had 0 confidence before this. I hate myself and my body so much. I know its normal for guys to look at things like this but I hate the fact of my boyfriend finding other girls sexually attractive and imagining things with other girls when I am his girlfriend. I feel so sick thinking about it. My mind keeps going over and over the titles of the videos and pictures he was looking at. The thing I am most worried about is my breasts. I don't have big breasts and the pictures and videos of the girls he was looking at all have big breasts. I feel inferior to every single girl I see with bigger breasts than me. I feel like they are better than me and the only way I can see myself getting better is if I get a boob job. I am on anti-depressants because of the pornography. I need help. I don't know what to do. I want my boyfriend to be interested in only me, I want to be so good that he will not need to look at other girls. Help.