pain near shoulder during squat. help.

[Suparaf]

Not long after I switched from high bar to low bar squats I started having problems with my left upper arm.

For like two weeks I simply couldn't squat. Just resting the bar with about half my workload would shoot some kind of electric jolts in my arm and numb it down pretty much completely. Now I'm 'able' to squat but as soon as I get to my workload it gets pretty painful. I just did 1x5 and had to stop.

The pain is just below my shoulder. I think my form is good and it's only on one side. I tried to use a wider grip but it didnt change anything.

Should I wait it out, go see a doc, use lighter weights for a while to see if it settles... ??

here's a pic to show where the pain is.