Here's what I think YOU SHOULD DO.!!! TAKE WAVERIDER"S ADVICE!!!
If you do have diabetes, you've got more problems than jeopardising your lifting...
I answered you in my first reply, you need to be evaluated by a medical doctor. Depending on the doctor's office policy he/she might see you w/o a parent/guardian present. As for having parent/guardian with you, I think the doctor's office might want it for insurance purposes. They don't want some random kid showing up getting treatment and not having a way to pay them.
My parents aren't concerned. I'm asking YOU what I should do. Not my parents. I don't care if your not a doctor. Just tell me what YOU think I should do.
You should discuss your concerns with your parents and see what they have to say.
But, do I need to be checked? I'm just curious becuase it could jeopardize my powerlifting. I really don't wanna see a doctor so....
Have your parent/s take you to see a doctor for a complete evaluation as we cannot examine you over the inet. Ask for a diabetes A1c [hemoglobin A1c] test, have your thyroid checked & tested, and get blood tests for hepatitis A, B, and C. Hopefully one of these test will uncover the reason/s for your health issues. Good luck.