Why might my arm be temporarily paralyzed when i first wake up? i am completely unable to move it for the first minute or so. i do rest my head on my arm sometimes, but ive always done that and only recently have i begun to experience this?

You are putting pressure on the nerves in that position causing the symptom. _Pl sleep with no pressure on the arm

The Head is quite heavy , and resting it on the nerves to the arms while sleeping can block and temporarily paralyze the affected arm. It might be a good idea to reposition/re-posture One's arms away from the head resting on it , if possible.