help please

hi everyone. ive been suffering from vaginal infections on and off for months now, im 19 years old, i have a regular partner and i believe i do hygenical stuff correctly. i pee after sex, i am very clean, i eat correctly and im trying to get away as much as possible from public wc. just a week ago i started feeling my vag burn and i immediately knew it was UTI because im having it for i dont know maybe 12. time in several months, i went to doc and i was right, i started antibiotics and today, i realized i am starting to have a yeast infection as well! i am so pissed, i have been to multiple gynecologistes(sorry for my english) and urologists and after using antibiotics for awhile, i also went to docs to get examinated when i dont have an infection they tell me everything is just fine. now im starting to think that i need to use probiotics or something else to help me.. i already tried cranberries and some probiotics and all the advice ive been given but apparently they didnt work. i dont know what's wrong but im so fed up with using antibiotics for 10 days and just when i start to think im fine i get another infection within 1 or 2 months. can someone pls help me to prevent having them pls im so desperate:(