Bladder problems

[tiki2t2]

I am 20 years old and about a year and a half ago i started having symptoms that seemed like a urinary tract infection. i had about 5 tests and they all came back negative but the symptoms persisted. i then went to an expert, had and exam, and had more in depth urine tests. he found a muscle problem that he said might be causing this bladder irregularity and i started bio feedback to work the muscle. it seemed to make a difference sometimes but the symptoms kept retuning in bouts or episodes. with the more in depth urine tests he found a rare bacteria in my bladder and gave me high dose antibiotics to get rid of it. however i still keep getting these symptoms in bouts and every time i return to the doctor the bacteria is still there. my doctor gave me a bunch of antibiotics to take whenever i presented symptoms. obviously these symptoms are very frustrating and sometime prevent me from doing a lot of things (sometimes from going to school). it's been a year and a half and the bacteria still persists. While i trust my doctor a lot i'm concerned that he's missing something. is there some other cause to this? how come in other people the bacteria goes away after one dose and i've taken many doses and the bacteria persists. how long will it persist before it goes away? should i be concerned that it's something else besides this bacteria (because it is so rare and normally does not persist like this). someone please help! i've been suffering from bouts of bladder discomfort and constant urges to pee for a year and half now and i've reached my wits end. thanks