How do you know when a friendship is over?

I've been gone for a minute, but I'm back with a new post *Lil Kim voice* lols. It's been a minute since I've done a post on here, but I will get back to posting. Whether it's from my laptop or from my phone. However I just got this feeling and I feel like I can no longer express myself in my diary. The pages are beginning to look a little bit too similar with the same sob ass story. So I figured why not get public opinion and finally give that story a new ending. So if you haven't seen the name of the post already, the question for this post is HOW DO YOU KNOW WHEN A FRIENDSHIP IS OVER? I want to know what signs are avaliable for me to determine whether or not one of my friendships can be saved or should that shit just burn in the pits of hell. A few months back, the month of February to be exact (month of my birthday) there was this big thing with two of my best friends from school. Long story short there was a new person in the picture. I was once formally cool with the person, but eventually that person ended up not liking me. The way I veiw things bitch stole my best friends. But, using more mature terms because I don't own them. I felt as though I was being replaced. Not only did I feel it, but other people seen it happening as well. Because I'm still a teenager I decided to make this girls life a living hell. Some other friends of mine joined in because they disliked the girl too. I know it was wrong, but I was caught up in the moment. Eventually the girl got my "best friends" to be against me basically. Since then we've squashed things but things has NEVER been the same. I'm a very very forgiving person. Sometimes too forgiving, but I thought after things were settled we would pick up where we left off in our friendship. That was not the case what so ever. The other girl is still in the picture and their always hanging out. So now it's like we're not even best friends anymore. I feel like some other irrelevant bitch. I've cried over this situation so many times and prayed so many times and still nothing. Here I am in August tryna make time and retrieve what we once had. Whats been bugging me is I'm not the kind of person to beef with anyone, if anything I'm the kind of person to be cool with everyone. I just want to be really good friends with everyone, but that seems impossible. I just can't wait for high school to be over altogether because I've literally been living a nightmare since my freshman year. I don't know what to do, but ask HOW DO YOU KNOW WHEN A FRIENDSHIP IS OVER?

P.S. I really want to post before and after pictures because the whole thing still trips me out, but I don't think it would be right to post pictures that aren't mine without the others permission. Just know it's something serious though.