Is this shock loss of overharvestin my donor area?

It is likely over-harvesting, but you must wait this out for 6 months as shock loss will usually reverse itself by then.  Let your hair grow out to cover it up.  You can use Toppik to cover the problem while it is short.  If it doesn’t reverse, then SMP by a good operator will solve the problem. Be sure to view the work of the SMP clinic you find, as seeing is believing and you don’t want to become a victim again if it was overharvested.