I have a soft swollen lump on the outside of the opening of my anus. There is some itching and discomfort, but no real pain. What is it?

Anal lump. Liklely a hemorrhoid, could be a skin tag or wart. Doesn't resolve check with your physician.
Could. Be a hemorrhoid or a small abscess. Try bed rest for 24 hours with feet above hips, warm tub soaks and intermittent ice packs. If no better or worse or fever or increasing pain see your doctor or a colon and rectal surgeon.