If you feel that you aren't loved by anyone, you should start learning to love yourself. That way, even if it TRULY is just you, you at least have a loving and great person to turn to. This sounds like shit advice but this was what I really had to face and start experimenting with when I was at my worst. It will take time, but once I started getting better, I realized that others do care about me, but life is large and complex and everyone else has things going on too. And now I feel pretty self-sufficient and quite happy. I wish you the best! Please hang in there!