I feel so alone...

I use to only have a few close friends. My best friend and her boyfriend. I didn't really talk to anyone else except for them. We use to talk about anything and everything. A few months ago, we all decided to have an open relationship. We were all dating each other. It was going well until my best friend and her boyfriend had a fallout. He was quite controlling sometimes and said rude things that were suppose to be funny (at least that's what he said) . My best friend had enough one evening when he had said something about breaking up and then promptly left her house. She broke up with him over text. I was in a bad spot. I broke up with him as well. He had pissed me off by talking to her like that. My best friend and I dated for about a week until suddenly in the middle of the night, she texted me saying she wanted him back. I was devastated. I told her it was ok if we just broke up because I wanted nothing to do with him. I just gave up. I have been dumped like this so many times that I didnt feel like fighting for it. They are together now. I began homeschooling. I don't go over to her house because I don't feel the need to see her and I don't want to see him. I don't have any other friends. On top of that, I have bad anxiety and depression. I have felt so poorly of myself recently and my life has taken a downward spiral. I don't know if I'm going to be able to climb out. Does anyone have any advice or encouragement for me? I could really use it. Thanks for taking time to read this.