I'm Just Curious About My Symptoms The Past Few Days.

I'm just curious about my symptoms the past few days. I'm usually very active. But since Saturday I've been very lethargic, hardly able to eat and this morning I was getting several dizzy spell to the point of almost passing out. I'm a bit better now, as far as the dizziness, but I still feel weak and lethargic and my appetite is nothing like it normally is. Any ideas? I also have the weird pinch in the middle of the left side of my back that hurts more when I try to eat.