I have drooping of my left shoulder and the "electric shocking" in my left hand sometimes too. My CRPS started in my left arm and hand and they seem to be the most affected.
The only time I feel drained or really tired is after a seizure episode which comes and goes at different times with various triggers.
I read so many people having the same issues as me which makes me feel somewhat of a kinship.
I'm sorry you're going through this and hope you find some sort of releif...