My relationship has turned up side down can any one help me?

ok, my boyfriend and i had started dating in june. the first couple of months were amazing! :) he called me beauitful almost everyday. and he couldnt keep his eyes off of me. he called me just to here my voice and to ask how my day was every night. but . . . we hit a speed bump in our relationship when school started we saw eachother everyday. sure it was great for the first month but as it went on we began to fight and argue about stupid childish things. like . . . people we didnt want eachother talking to and giving eachother wrong looks . . . ( told u it was stupid ) . . we broke up over some gurl that clamed to be dating him the same time i was. . idk if it was true but he broke up with me saying he wanted to date her and that he liked her . . i told him he was a player and to **** off. . well 3 days later he dared to talk to me. he told me that it was a miss understanding and that he only said that to have a reason to break up with me because he needed a break. ( i mean he could of just said that in the first place and saved a heart break ) but any way i took him back . . thinkin he's changed then it happend again! with the same girl !! she told me they were dating, i acused him, we brok up, now we are dating AGAIN and everything sence then has simmerd down. but he has changed . . he tells me he loves me, and that i am pretty ext. . but he wont hold my hand, hug me, or even kiss me in publice ( school ) he did b4 so he isnt PDA fobic. but he asks for all the time and he wont let me see his txt messages . . and i dont mean he is playin with me not letting me read them its . . . like . . . when i grab his phone from him he tackel me to the ground to get it back . . . is he cheeting on me?? idk wat to do . . . i love him so much . . we have been together for 7 months now and i couldnt imagin my life with out him please help me! i need to find away to get the man i fell in love with back please . .