No uti, no prostrate issue, all tests ok.have feeling to urinate all time after going, bladder tests normal. sometimes stiff back and itchy uretha?

Hard to say: Hard to say with out more info. What bladder tests were done? Have you had a cystoscopy done in which direct visualization of the inside of the bladder was done? A biopsy? It sounds like cystitis, which is an inflammatory condition of the bladder, but there are other potential causes as well. Be sure you are being thoroughly evaluated by a urologist.