What is wrong with my bladder? ?

I'm a 14 year old male and I have had this urge to pee right after I drink somthing (legitamately like 10 minnutes after I drink somthing I have to go) and then after I go I will need to go again like 20 minnutes later ?? This has happend scince january and I already know its not diabetes because this morning my blood sugar was 86 and I've been to the uroligist like 5 different times and for some odd reason he thought it was my prostate...... yea I said prostate=/ and he gave me like a bagillion urgency pills and prostate pills and anti biotics and none of them worked (this was back in july!) So now I still have the problem and I'm in tears because it controlls my life at school and at home and its the utmost annoying thing I have ever had the displeasure of having..... so if you guys have any tips on what to do or what this is it would make a 14 year olds day=(