HELP please! i dont know what to do D':

well, the other 日 i found out my boyfriend was texting this chick. But im cool with him texting girls, but not when he's putting 爱情 hearts in and stuff.
He doesnt talk to me much anymore at all. And i was talking to his best friend, and he told me he was going to dump me, but then he decided he wont.
He's not giving me the 爱情 and attention that i need (that sounds weird, but yeah).
And i dont know what to do. My friend likes his best friend, and she gets to see him when i see my bf. So if i dump my bf, im not only breaking his heart. I dont even know if he would be sad.. I just really dont know what to do. Help?