I sometimes feel too full after a not-so-huge meal. I do mot move too much or too little, but the feeling in my stomach is so weird: it feels like it's too heavy for me. Afterwards, I throw up, and when I look at the vomit itself, the food particles are still visible (i.e I still see small particles of hotdog in it). Then the heavy feeling disappears. What do you think, what's wrong with me?

You could have a condition known as GERD... or another name.. Acid Reflux. Please see your doctor for a proper diagnosis.