Swelling and tightness when I sit?

[notinsane]

A short background of my problem - I took a strong antibiotic in Feb and immediately noticed an anal itch which gradually got worse. Used Prep H cream for a while and taking daily salt baths since Feb, went to doc in March and no hemorrhoids found, just dry and damaged looking skin. April I was prescribed anti-fungal single dose plus an ointment to use daily. The itch faded away quickly which makes me think it was yeast, but the feeling of swelling, dryness and stiffness persisted and got worse. When I sit it feels like I'm sitting on something, a very tight feeling like something is going to pop. Especially bad if I've just washed the area. I have no trouble or pain going on the toilet, I'm somewhat regular and not passing anything too strange looking (though my gut was messed up for a while after anti-biotic).

I don't know if it's the skin on my buttocks or something rectal / internal. I thought maybe I've been putting too much ointment and water on the area for too long and I've possibly damaged the skin. But I also worry that maybe it's something internal like a deep abscess or tumor. Again, not really painful, no blood, no other symptoms. Just an uncomfortable tight, dry, stiff feeling that gets really intense when I sit down, especially in a firm seat. Usually early in the day it's not as bad, but gets worse later.

I've been examined twice to no definitive conclusion, just guessing on the doctor's part. Maybe it's internal hemorrhoids, or maybe it's a fungal infection. The stiffing I'm feeling they said, is probably just the skin folds where they're infected. But two weeks later, the same, if not worse. I can't stand to sit down.