Why is my food not digesting?

[rjm242002]

So I have noticed that my food is not digesting. My upper abdomen is always bloated and hard where my stomach is. I feel full even if I go a day with out eating. I'll vomit every three days and before I do I have rancid burps. My vomit tastes fermented and food from days ago comes up. When my stomach is empty I don't feel full and I feel hungry again. I don't know what is going on, but it hurts. Anyone know what could be happening?