Heaviness In Left Side Of Head, Nausea. Advise?

hi , i woke up this afternoon and had heaviness in the left side of my head , there is no pain but this heaviness was causing my body to fall on the left side , i literally had to take support of the wall or chair to walk, at the same time i was having nausea feeling. now after 2 hours im still having the heavy feeling in the left side of head and as i suddenly get up form chair the nausea feeling starts again then walking makes me feel better. i barely had lunch because of nausea feeling. this doesnt happen to me often, but i doubt this may be due to air condition, or i do daily yoga that may have been causing this. its just not stopping please help me get over this nausea feeling and the heaviness in head.