My bladder/vagina burns when I don't drink enough water?!

i have had bladder problems since i was little. i was always wetting the bed and got bladder infections. well im a 22 year old woman now. i have a very weak bladder. all of my friends know that i pee all the time. i think it might be hereditary because my aunt and my mom are like this too. well anyways about the water thing...i have to drink alot of water everyday. if i skip a day, that horrible painful feeling comes back. it feels so uncomfortable i cant even describe the pain. its like a burning pain, but for some reason i have to be alone when i feel this pain. my family came to visit one time while i was having the pain and i hid in the closet. i just cannot be around people while its happening and i dont really know why. to make the pain go away- i drink water. also...after my morning pee i have this pain VERY badly. im just concerned because people go without water all the time and they are fine. i never hear of anyone complaining about how they took their morning pee and now their bladder burns. i am really concerned about my health. someone plz help :/