I had this (tennis elbow?) a while back – riding the bike was not a problem, but lifting it was quite painful.
The two things that helped me were a course of anti-inflammatories (administered by a fairly big stick-on patch)and being careful how I positioned my arm whilst sleeping.
It’s tricky to explain, but I’ll try…
I used to sleep with one arm under the pillow, in a “flexing my biceps” kind of pose. (no sniggering at the back!)
I now keep both arms bent together in a kind of praying pose.
I’ll try to find some appropriate pictures and post them later.
Definitely go and see your doctor though – I’m not a professional (unless you count professional geek)