No one understands

I really have no one to vent my feelings to like there is really no one,no matter how much i try to make myself feel better somethings off.My bestie of like 8 years almost literally starts to cut me off.She does not talk to me neither she want to hang out with me.Recently she has gotten herself a new "friend" whom she calls all the time and they laugh together no one really is there for me.In the past we used to be together all the time i really loved her but ig she never did thats the reason she does not care about how sad and lonely i am.Also i have started uni recently and its taking a troll on me i literally have no friends i am always alone and depressed what should i do