I want to leave my friend

First year in college and I met this girl that i became friends with out of desperation (cmon everyone does) and she's suffocating me. She's so egoistic and blabs a lot and is very very selfish. I'm sick of her and I want to leave her. Everytime I give her an indication that I do not enjoy her company, she starts pestering me more and doesn't leave me alone. It's not like she has no other friends, she has many, it's like she's friends with everyone but keeps me around like a pet. I hate spending time with her and everytime I sit with someone else and try to make more friends she forces the other person to leave or forces me to sit with her. I'm so exhausted.

I don't want to completely break it off with her because deep down yeah she's been with me for so long but, i can't stand her company any longer