I fight against depression, and have had these thoughts too sometimes. All of my friendships had seemed to just fade away and I was left with nothing. However, when I looked back at my messaging history, I realized that I hadn't reached out to them in years, and a lot of the time, the conversation stopped with me. Since then I've been sending messages to old friends and every one of them has been excited to hear from me, many wondering where the heck I've been. Hang in there. You're not alone.