<human>: First im not really sure if this is the right sub, i honestly could not find a better one to post this in.

Some background info: Me and my whole friendship group have had this problem before with this girl. we will call this girl i hate M. In the past few weeks M has been sucking up to my best friend. they can be friends thats none of my business. But what gets to me is she hangs around with us every second she can. My friend, who we will  call A, is constantly being followed by M, but she doesnt mind. 

A bit of info on me, i had depression for a year or two, im pretty sure thats gone for now, but i have a self harm obsession. A knows this. M is a massive trigger to me since she has said things about *starving herself and jumping infront of a car* without actually meaning it, which pisses me off.

There where/are 4 people i can trust 100%. I had a fight with one because i was to much too handle, one is changing school next year, one i dont know as well as the others, and A. If A becomes best friends with M, that only leaves me with one person i can go talk to during the day. The other one thats moving schools will only be available on weekends even though i could still talk to her through facebook. 

I really don't want to lose my best friend because i really need her. I don't just want to lose her, *I need the support.*

I know im sounding selfish and i really can be a bitch if i want but then again id rather have someone i can always count on than being sad, alone, depressed and harming.

Can you summarize the given text in a few sentences?
<bot>: I can't be with my bestfriend without being with a triggering girl who makes me want to self harm who is trying to take my spot as best friend.