Jeff, I am going to go straight to the issue: You bruised the bone in the actual joint. That is NOT A CALLUS. The swelling, the bump, is what the bone does when it gets banged enough in that area right at the joint.
The good news is that it will go away. The bad news is, it will take several more months. Could be 6 to 12 months depending on how badly you irritated the area.
While the bump is like that, even if it feels better, continued banging of that very small area will make it worse fairly quickly. And as you repeat it, until the bump is gone, it will get worse than before, each new time you aggravate it.
The sanding of the edge information was correct. But the degree of sanding is what you may be missing.
Where your finger is on the FH side of the blade, you need to sand that down almost all the way to the Carbon on the BH side of your blade so that your index finger is on a completely flat surface that is the same angle as the angle of your index finger in your photo.
That will help AFTER THE BONE HAS HEALED. However, for the next 6 months, my recommendation is to get a shakehand blade and learn to play shakehand for a while. Doing that will ultimately help your penhold game improve anyway. But that will allow you to play and it risk making the injury worse.
Otherwise my recommendation would be, don't play for 3-9 months (until the bump is FULLY GONE).
As of now, the injury is not serious. But if you keep re-aggravating the injury, at some point it will be.
Sent from the Subterranean Workshop by Telepathy