Burning when urinating for 5 years

Has anyone else experienced this or can anyone give me any advice please? In 2017 i got with my boyfriend, we had sex for the first time and i got a UTI which did not go away for 9 months, i was on antibiotics everyday for 9 months. The UTI finally went away but 5 years on i still experience burning when urinating and sometimes even when i'm not. I have to drink so much water everyday for it to not burn. I have had UTI's since which have only lasted a few days - a week then gone away with antibiotics. I have been tested for STD's which all came back negative, my boyfriend showers before sex and wears a condom and i shower & wee before and after too. I have taken BV pessaries in the past which have given me some relief but the burning still comes back. I don't really have any other symptoms apart from pain when weeing. Could my bladder/urethra somehow be damaged from 5 years ago? could the antibiotics have caused an imbalance in bacteria? I forgot to mention that my diet is really healthy, i drink loads of water, eat minimal sugar, i take a probiotic & cranberry supplements. Before 2017 I never got UTI's nor did i ever experience burning or any vaginal problems. Any advice would be greatly appreciated, thank you in advance

Showering before sex, makes the outside clean, and partially internal, but that doesnt necessarily get rid of sexual infections.