Random Burning Sensation In Vagina. Diagnosed Yeast Infection After UTI, Taking Medication. How To Cure Completely?

Hello, recently, for the past 2-3 months I would say, I have been having random burning sensations down in my vaginal area. In June, I had a pretty bad UTI and went to an Urgent Care center because I was out of town and it was treated. After that was cured, it felt like I kept having regular burning down there still, not when I urinate just randomly. My doc said I had a yeast infection after the UTI and so I got medicine for that and I had irrigation down there so I tried a cream. A few weeks after that I still felt random burning. I recently went in and the doc said I still had some yeast infection and a bacterial infection really inner. I took a pill for the yeast and a gel insertion thing for the other infection. I finished both prescriptions 5 days ago and I felt like it was practically gone. However, my boyfriend and I tried intercourse last night and it was fine at first then burned terribly and today it has been burning randomly again.

We both have been checked for STDs and both negative and we've been each others sex partners for four years now. I'm not sure what's going on, but it's burning randomly and during inter course and I just want to figure out what's going on because it's very uncomfortable and definitely want it to go away, NOW!