Hi Gene Eric,
Your statement that you have no idea why your condition is as such, and that you have been thinking about Lyme’s and other possibilities for you pain/movement impairment would indicate that you have no diagnostic image (X-Ray/MRI) verification of a Rotator Cuff injury.
If that is true, it’s possible that you have Adhesive Capsulitis (Frozen Shoulder).
http://orthoinfo.aaos.org/topic.cfm?topic=a00071
It’s worth investigating in any event.
Thanks. I’ll check it out.