Hi, I Am 56 Year Old Male. I Was Diagnosed

Hi, I am 56 year old male. I was diagnosed with prostate cancer last April, I was 9's on the Gleason scale. I had robotic prostatectomy in June. Since my surgery I have had problems urinating while sitting down, I can stand up and drain my bladder. I did have some bad UTi' post surg. I my Urologist has me on Vesicare for 3 weeks now and no changes. I also experience this while laying down for the night, and I wake up in severe pain. Any Ideas