DT78, you've got or are getting cubital tunnel syndrome, basically the nerves where they run through the elbow joint are being strangled, if this is left untreated it can lead to permnent loss of use of the fingers and as you say possible muscle wastage.
If you use a PC for any length of time each day you need to stop or reduce to a bare minimum and for no more than an hour at a time max. I would also stop riding the bike for a couple of weeks as the jolting/vibration can aggrivate it.
Get a shed load of ibruprofen to reduce the inflamation in the joint.
If after the above it doesnt go away you need to get refered to a orthopedic surgeon.
Dont just think it will go away on its own, it rarley does and I've got the surgery scars on both elbows to prove it!!