Could I be Lactose Intolerant?

Normally lactose intolerance causes diarrhea and flatulence. Soy milk however is free of lactose, so perhaps it is more of a protein reaction. You may try almond milk, its very good if you get the vanilla flavored. And there is also rice milk, but I have never tried that. If this is the only food that gives you this response, then you may need to avoid it all. You can get calcium from enriched orange juice, almonds, broccoli, salmon etc. You get phosphorus from meat, and magnesium can be found in a varied diet of fruits, veg, and grains. Vit D is also included in OJ. Also a simple multivitamin/mineral would help fill in the voids. Keep in mind, sometimes, a response like you are describing can be psychosomatic...you have been ociating bad feeling with milk for so long that you get nervous when trying anything else different. Good luck with this, I hope you find some resolution.