What should i do about my "friend" ?

I'm starting my freshman year tomorrow. and i've been friends with this girls for about a year now, and in the beging we had a really good time together and hanging out . but then she started being more and more depressing and since she was felling that way i also started feeling more sad and depressed and i kinda took it out on my family... so i stopped hanging out wit her , and made up an excuse that i wanted to get closer to this guy i liked, so i started hanging with new people and got happier and we now kinda have our own little group ( we are not popular by the way ) and wen she tried to hangout wit us everything would get awkward and silent. so we would hardly talk anymore. and now she got a new cellphone and only has like 4 contacts so shes texting me all the time , but its annoying cuz she always asks me about money and how much clothes i have, cuz I'm wealthier then her but it gets annoying ... so i dont want to be her Friend anymore but idk how to do that. and she is such a poser she trys to act all emo! its stupid !!!! and she makes funn of everyone ! and is just so mean! so please help me !!!!