uncomfotable tommy

I remember while growing up as a little girl, I use to hold my urine for a long time before i head to the bathroom. And i had continued this till my adult life. About 5yrs ago, i did it again and i felt pain for the very first time and since then i haven't been comfortable whenever i have to urinate. I get really bloated and uncomfortable and even sometimes when i wake up from sleep i feel uncomfortable and bloated like i have alot of urine backed up in my stomach and that's when i know i have to go to the bathroom. I been to the hospital different times over the yrs, they have done ultrasound, CT Scan, etc but they don't find anything, they have even done blood work and still nothing but i know how i feel is not normal. Now when i get bloated and uncomfortable and go to the bathroom, i only void alittle. I get alot of tommy ache. Can u please help?