Finally got an appointment with specialist to talk about the moving nerve pains in my arms and it turns out long term tendonitis in my forearm, caused me to overwork/strain/slightly tear my bicep, which in turn caused my elbow to swell and flare up, which in turn caused my posture to adopt a kind of locked/chicken wing position to compensate/control the pain, which in turn compacted my shoulder muscles into pinching a nerve cluster which is why certain basic movements cause blinding nerve pain.