If you feel you have all the symptoms of diabetes, you need to go to a doctor to get checked. I'm sure your parents would want you to talk with them about it and be seen be a doctor. If in fact you do have (Type 1) diabetes, exercise and eating healthy are very important and it's great that you do that, but they will not get rid of diabetes.
If you have diabetes you need to see a doctor and get treatment. Please don't be scared of this or try to avoid it because the results of untreated diabetes can be very severe.
zoelula is right. go to a doctor and get checked it might be nothing. always best to make sure.
If you are diabetic and you don't get seen by a doctor SOON you could wind up as I did 28 years ago - in a coma. My blood sugar was up to 880 and I was constantly hungry, thirsty, potty breaks, annoyed at everything and always falling asleep. By the time I got to the doctors office and they found out I had fallen asleep (again) and gone into a coma for almost 2 days.
Diabetes isn't a horrible, nasty, awful thing. Is it fun - NO, but it is manageable. Just show your parents this site and all the info you have been given. Any doctor will be able to tell you with a simple blood test if you are or are not diabetic. Hope this helps.