Hello. My Ct Scan Showed Underdistended Bladder. Is That Why

Hello. My ct scan showed underdistended bladder. Is that why I have to pee so frequently? I feel as though I am done and then a minute later, have to return to pee some more. Is there a cure for this? Yesterday I ended up in the ER because I could not pee although I felt the urge. First time that has happened. I may have been dehydrated and scan showed only 31ml urine in bladder. So why did I feel the urgency to pee? thank you for any advice your can give.