Vagina burning.. TMI

So I have had vaginal burning for 3 months now.. I’m 19 years old and I have been with only two people, and the person I’m with now for a year. It started off in November when I had sex with my boyfriend and the next morning it was pretty painful to pee, a few days later I treated it as a yeast infection/urinary tract infection. I had clumpy white discharge, no horrible smells, burning when I peed, and the worse burning sensation in my vaginal opening!! Things felt better but not completely gone. I went to my pediatrician (yes I know I’m too old to go to him but after 19 years he’s the fastest doctor to get me in and be seen) and he ran a culture for yeast and a urinary test and they came back negative but he still gave me antibiotics and they did help but now every time I have sex it burns, and is very painful for me, when I have my period is burns so much and is worse around that time, sometimes it just randomly burns in the middle of the night when I go pee.. no discharge, itchiness every now and then to the point where I start bleeding from scratching, and I have 0 sex drive anymore because it hurts and burns so much. Sometimes I stick a finger in there and the burning immediately starts happening as if I have cuts?? I have sex maybe once a month sometimes not at all as I am in a military long distance relationship.. I would think those “cuts” would have time to heal? I’m feeling really discouraged and I don’t know what to do. My boyfriend has been tested through the military as part of a mandatory check up and he was negative for everything, therefore he couldn’t have given me anything and the boy before him he was a virgin and never did anything with anyone so couldn’t have caught anything. I just really would like someone’s honest opinion on what to do before I go to the doctor so I don’t go in clueless and not know what to ask.