What Is The Reason For Feeling Heavy While Eating Food?

I get a reaction while eating meals on occasion that makes me suddenly feel high. My whole body gets heavy. My fine motor is off and my speech is slow. My thinking slows down and I feel like I need to hold onto someone to safely walk. I have been on a wheat free diet for over 10 yrs from an assumed wheat allergy, like my dad has. I got tested last year and was told I am not allergic to wheat, but I am allergi to cow s milk. I wasn t told to avoid dairy, but find my tummy doesn t take too kIndly too it. What s going on?