I know you haven't asked me, but I feel like all of us face similar problems in PE.
You have overtraining the most common negative result.
Second place would have to be a thrombosed vein which goes away with heat, and medicine.
The worse one would probably have to be numbness which can happen from stretching too aggressively or blocking blood-flow to the member. That could take longer to heal.
I have had vein hardening which can be avoided by applying a proper warm-up which doesn't require a heatpad. Simply regulate the force in the beginning to be less than the climax of your session. Like engaging all the shifts in your transmission to get the most horsepower.