This is not at all what 16 year olds want to be doing with their time. Your teens are a time to hang out with friends and to develop the self-discipline and motivation you need to go on with your studies and to think about what you want to do with your life. I’m so very sorry that you seem to be unable to enjoy your family and friends lately.
The first thing to do is to see your doctor for a physical check. It’s possible that there is a medical reason for your withdrawal and over-sleeping. Hormone imbalances are often the cause. Another possibility is that your sleep cycle is so disrupted that it is affecting your mental health. If you aren’t getting 8 hours of uninterrupted sleep every night, do talk with your doctor about how to get yourself back into a normal routine. At your age, especially, the body needs restorative sleep every night.
I also hope you are getting some physical exercise at least 3 – 4 times a week. Being active will help you feel better physically and mentally. If you don’t enjoy sports, you can always take a brisk walk, or go for a run. When you do, the body will produce endorphins, a natural body chemical that lifts our spirits and our sense of well-being.
If you are sleeping well, eating right, and getting some exercise and your doctor tells you that you are physically okay, then it’s time to see a mental health professional. It’s possible that you are suffering from social anxiety or depression or both. In that case, some therapy and maybe some medicine can help you get back into life.