That's a really difficult feeling. I made this realization a long time ago, and I wanted to believe my low self-esteem was just making me think the worst of people, but I did lose a lot of my friends last summer. The situation was complicated, but after a long time of reflection, I realize now that I clung to bad relationships from a desperate desire to feel loved during the worst of my mental health struggles, which caused my friends to distance themselves from me. While I understand their reasoning, I wish the situation could have been handled different; perhaps, I could have escaped a bad situation sooner and still retained some genuine friends in the process. But, I know that they weren't always the good friends that I made them out to be, even though I adored them with all my heart. I've made new friends since then, but I don't feel nearly as connected to them as I did with my old group of friends. Cherish the good friends you have; those people will matter the most in the long run.