Sharp Pain I Lower Abdomen Sometimes Continuing To Kidney Area. Any Ideas ?

For three months now i have been going to my doctor non stop and am now being referred to the hospital for further tests. im 21 and i am haveing severe pains in my lower abdomen which continues round to my kidney area. I am also always going to the toilet (urinating 20+ times a day) i have done various urine tests etc. i recently had an ultrasound to check for kidney stones or ovarian cysts , but again nothing was found. I have had four different antibiotics incase of infection, and yet still no difference. i also the whole time i have been going to the doctor, have had blood and protein in my urine. any ideas ? Also i dont know if this is helpful or not, but diabetes and endometriosis. thank you