What Causes Persistent Swelling In Vaginal Lips?

I have had this swelling in the area of the vagina...could be lips of just right inside...have had this for about 4 years...have been to 4 different doctors...and they see nothing wrong...in November the doctor thought I needed hysteretomy something falling down, after surgery waited to feel normal with no swelling....has never happened. It is hard to walk and makes you tried... I m walking in a college pool and no problem at all...but walking on land for any length of time...like the lips are crossing over...makes me very tried and uncomfortable...who should I see....have seen 3 very good gynatolists. Take several presciptions for heart problems...had a stent about 4 years ago. Any ideas?????