Boyfriends EX is way prettier than me..?

[523]

ok..well.. hes not officially my boyfriend. but he tells me all the time he loves me and we hang out all the time. anyways, hes always talked about his last girlfriend of six months, that he dated about six months ago (who lived with him). she cheated on him but he said that if they didnt live together than they would probably still be dating to this day. so i asked about her..he showed me her instagram and holy cow she is gorgeous. like..he downgraded. like you cant just go on stage after beyonce just performed... well now im really self concious and ive hardly talked to him for the past day because i feel like hes just playing me. if he can get a girl like that what would he want to do with me? ok im not ugly but im really not pretty at all. i know how girls all the time are like "oohhh im not pretty ohhhh" but im really not. im just the average sally.. i cant believe it when people tell me im pretty, like i feel they are just telling me that to make me feel better about myself. so whenever people tell me that i kinda get mad at them and resent them...
anyways, shes gorgeous, i cant compare, anddd now idk what to do..any suggestions?