Shoulder/Neck ligament problem?

This has happened a few times while playing rugby however during the worst and most recent incident I nearly lost consciousness. Basically whenever I make a big tackle with my right shoulder I get a shooting almost cold or electrifying sensation from the base of my neck to the tips of my fingers. Once I even started seeing green spots everywhere for about 5 minutes after it happened. My right shoulder is also slightly lower than my left shoulder which I have seen before happen to another rugby player. I went to a clinic and the doctor told me there was a,igament problem, prescribed Turadol (which had no effect) and told me to keep off the shoulder for three weeks. I was going on vacation for three weeks so it worked out perfectly, however it didn't get one bit better. Also whenever I look to the right I get a pinching pain at the base of my neck/shoulder that is more intense when the shoulders are hunched. When I windmill my right arm there's a kind of popping happening right around where the pain is and when massaged there's definitely some kind of knot that will not come out no matter what. I've been off my shoulder now for close to three weeks because training is stopped till after Christmas however it still isn't getting better. Thanks for any help.