Living like this is so painful

21M) For the longest time, I’ve been feeling extremely lonely. Usually, I’m good at dealing with it and just moving on, but lately, this feeling has been eating me up. Something about living every day alone is soul-crushing. I think about all my old friends, and I find myself asking, “What did I do for you to leave?” or “What is wrong with me?” It crushes me whenever I see them forming strong bonds with other people.
Sometimes, I wonder how many people think about me or how many people actually wonder how I’m doing. I need help badly. This feeling hurts so much that sometimes I genuinely can’t breathe, and I don’t want to feel like this anymore.