First back up. You said you weren't feeling well. You mean physically or emotionally? Cause my whole adolescence (and 30s) was like this. I had to take myself out of everything because I was having severe mental issues like racing thoughts, anxiety, irritability, abnormal moods, etc. and was really disconnected to myself. And I couldn't hold a conversation to save my life and it ruined all of my relationships and no one could understand me.

If your symptoms were emotional or mood I can completely relate with you. I never found a way to tell people that I knew that something was not right. In fact, lots of people get defensive when you have trouble giving them attention (due to emotional problems) and they turn it back on you and stop being friendly.