I dont know if my boyfriend is taking advantage of me. Can you let me know if you think he is please?

My boyfriend and i have been together for almost 2 years.We were so good the first year with no arguments and then they suddenly start to happen. Everyone thought we were a really happy couple and were always happy for us. Then one day we had a big fight and he just said "you know, what its over" then he left. i didnt think he was serious.i pretty much begged him back and he would tell me to not wait (he was such a different person) he would flirt with girls on myspace. when i would call he would text girls while i was on the phone crying so much,trying to work things out and talk and he didnt care AT ALL! then i went to this concert and we both ended up in the first row and he was texting girls in front of me.i wanted to cry so bad but i held it in. i went through days without eating.my eye had a red spot for crying so much.i let him know all this and he would tell me "karina you can wait if you want but im not making any promises" he was just so rude to me, it hurts just thinking about it. then he pretty much told me "lets do things with other people then get back" i didnt like that at all. then i text him "if you do anything with anyone i wont take you back" he called so mad and said it was over for sure now,that he was testing me to see if i trust him. i couldnt believe he was testing me after everything and i wasnt able to focus most of the time because i was going through depression! i cant believe he can test love like that and everthing else. i didnt text him a whole day and then he text me saying he still loves me. i give in to easy and thats another thing.when we took that 3 week break he came to my house to talk and he told me the things he did with other girls.i didnt do anything with any other person because i love him and i also didnt have the temptation to. he told me that he was hanging out with his friends and there was a girl there.he got reallyyy drunk where he couldnt remember anything and his brother put him in a room to sleep and then put that girl and they had sex without protection :'(
then on his birthday i went to his house to give him his present and we kissed and said i love you.he looked so happy.i asked him "we're still on a break right? we are gonna get back together when you're ready right? he said "yes baby" i cried so much in front of him because i missed him. then he went to this girls house the day after that lived 45 minutes away and he let her kiss him 5 times he said.that was on our break but the day we got back together he said "can i still talk to her and invite her to concerts? its not her fault that i didnt tell her about us" he was saying he still wanted to talk to her cuz she was cool and he felt bad cuz he didnt want to just stop talking to her.

i feel like i took him back to fast.he told me if i did something he wouldnt take me back.he said he couldnt be as strong as me.now that we are together he doesnt try to win my heart back.he seems different. he's mean to me.then one day he got so mad cuz i was asking for advice from his friend cuz he got cheated on too and my boyfriend got so mad and said "F you" to me and drove off and i chased him with my car and called so many times and cried so much. he said i was sluty if i went camping with some friends without him(my boyfriend) im so faithful and he should trust and treat me really really good after what he did to me! he broke my heart! and it feels like he doesnt care to make it better.

is he taking advantage of me?