burning

i’ve had 1 partner for 3 years, i’ve been tested every 6 months due to my immunocompromised disease, and due to the meds i’m on i have to use extra lube due to dryness, but i’m still getting a burning sensation that last for at least 5 minutes after sex. i pee right after even though it hurts. i’m in tears every time. when my partner puts it in i tense up due to it being uncomfortable, no doctor can figure out my problem. but i do tend to take a lot of baths because of the pain my body is in.. i just want to be comfortable when we have our sexy time together!!!