Constant pain in vagina please help!!

Ever since i had a uti for the first time, i have a constant horrible stinging pain in my vagina that doesn’t go away until after i’ve drank about a litre of water and then i have to wait for the need to pee really bad before i can pee without it hurting and the pain finally stopping. if i push on it with my hand it stops the pain while my hands on it for a minute but that’s it. it’s normally first thing in the morning, when i’m trying to sleep and am not drinking, and if i’ve been in tight clothes for ages. even so i have to be constantly drinking a lot all day. i take cranberry extract and probiotics but they make no difference. i also eat healthy and exercise, i’m a healthy person. i also haven’t had sex in nearly a week so it can’t be that as the pain is just as bad as when i do have sex. it’s not an sti- been tested and been with boyfriend nearly a year. i’m scared to go to the doctor as they just keep prescribing antibiotics to my friends who have this same problem and i don’t want that. anybody have this and have any tips??