Could I be depressed?

It sounds like it could be depression. Try going out more often with friends and getting into sunlight as that is a natural mood elevator. If you don't want be on medication, don't. It's your choice. Instead try to do things that make you feel happy or that make you feel good about yourself. Maintain a healthy diet , get regular sleep, and exercise. These are simple steps to help you with depression. Many if not all people have dealt with depression at some point. Based on what you said, I think you may just feel lonely and that has triggered it. Try going out with friends and doing new things. Good luck :)