This is Olivia
In high school I had a succession of best friends. In grade 8,9,10-11, and 12 I had a new best friend each year. This was because being best friends with someone, I put all my eggs in one basket, and I felt that if they did not do the same, they did not value our friendship as much as I did. I had this fear that as soon as they made other friends, or got a boyfriend, or had other priorities apart from me, they would dump me as a friend all together. Looking back, I realize that what I was thinking was childish and foolish but in the moment I felt justified for completely cutting them out of my life and to "test" them by seeing if they would text me first, or ask me to hang out first if I stopped trying all together. It usually followed with them not talking to me because they probably felt that I didn't want to have anything to do with them.
I then had a realization of my actions when I had this best friend from grade 10 to 11 who I was literally attached to the hip with. If snap chat streaks were a thing then, we would have hit 2 years easy. However, going into my senior year I felt that I hadn't connected with as many people as I had wanted and so I made the effort to make new friends with the people I had gone to school with for 5 years but didn't really know. I can't speak for what my best friend felt, but if it was anything like how I would have, she was probably hurt and felt that I was bored of her, or was dumping her, which I wasn't. I made a few good friends and through the experience of it all, my best friend and all of her friends dumped me. I thought everyone was out to get me and that my life was coming to an end because I felt isolated by someone who I considered to be my best friend forever.
I victimized myself for a couple months but then realized that I did the exact same thing to several people before this. I realized that I knew how she was feeling, and I didn't reach out to her like I would have wanted if I was in her shoes. Although it took me a while to understand why it happened, I figured out that the whole thing wasn't out of hate, but out of hurt. I learned that how I was treating people had no rationale because no friend "dumps" another, unless you purposefully make that happen. Although it took a few months, and a lot of tears, I figured out that my insecurity and fear made me the problem, not the other person. Since then, I've worked on having confidence in other people and in my friends.