since how long you are having this discomfort or pian?
is there any vaginal discharge or rash?
Do you have increased frequency or urination?
is there any chance of having STD?
please provide more information.
I think here you are dealing with two prblems at the same time.
Burning sensation upon urination is a common sign of urine infection. it needs to be tested to confirm it and if UTI, you will need antibiotics to get rid of it.
Vaginal area infection.
Increased sensitivity with burning sensation seems like infection untill proven otherwise by physical examination. even though you use protection, there is always a chance of having infection even it may not be STD.
so please visit local physician for physical evaluation and tests and get treatment as soon as possible.
Meanwhile drink more liquids to wash bacteria from urine.
drink lot of water before intercourse and void urine after it as it will wash away bacteria introduced during intercourse.
Always wipe from front to back. it will minimize the risk of having urine infection.
drink cranberry juice. it helps to minimize burning.