Recurrent Urine Infection, Bladder Fullness, Slight Fever. Urine Test, Ultrasound Normal. Took Medicines, Problem Persists. Suggestions?

Hi... I seem to have urine infection and it feels like my bladder is full all the time and i can feel it all the time. I had something similar 5 months back and i took T nurflux , T pam-d, syp cital by going to a doctor. I also did unine test and even ultrasound for precautionary sake. They both were normal and after having medicine it was fine. I have again got this infection... and have slight feeling of fever .