Break up with himmmm?

Alright! I'm in high school. And ive been dating this guy for 8 months. I did lose my virginity to him:/ I feel like I'm wayyyyy to young to be having sex. I know i am as a matter of fact. Anyways he means alot to me and i know i mean alot to him for various reasons. Well school ended about a month a go and this girl lena wrote all over his truck with car paint saying i love you and she put hearts everywhere. SO i flipped i went off on her because that was disrespectful in my opinion. (im all about respect, i have an old soul.) she apologized over and over and said it would never happen again. And my boyfriend also said he hated her and he would never talk to her again and he told her to **** OFF and leave him alone. buuut now she likes and comments on his pictures on facebook? and texts him all the time. I dont about you, but...if some guy told me to **** off and leave him alone i wouldnt be texting him constantly and liking all his pictures on facebook. just sayin. another thing is, is he wont let me hangout with other guys because "im too pretty" and "he knows how guys are". WELL i dont tend to get along with girls very well. I have way more guy friends than girls. but then on facebook some girl said we need to hangout! and he wrote back LETS DO IT!! like really ************? I really just dont know what to do. Everytime i go to break up with him he just tells me hes so in love and i mean everything to him and he starts crying. fuuuuck please help:(