so sorry to hear this, and i hope it passes for you soon. i have 1 finger on my left had that has been numb for a few months now. and not 1 of the DRs i go to know why or what is behind it. my PCP gave me Bcomplex thinking it was my low B12. my nuero has run countless tests on me and no answers yet.
i so pray your arm doesnt stay this way for long. if it does maybe you need to see a nuero about it.
still looking for answers.
Remember that advice is free, its your choice what you do with it. :)