I found a hard pea-sized painless lump just inside my anus under the skin. I do have hemorroids, but this lump is not soft and not painful.?

It is most likely. an "old" clotted hemorroid! These wind up as tiny lumps (old clots) in one of the small veins! You can easily have this checked out in a routine office visit to your PCP (Primary Care Provider..with a simple rectal exam! Hope this helps! Dr Z.