For About 2 Months I Have Been Having Stomach Issues.

For about 2 months I have been having stomach issues. I have been having stomach cramps, pain. Sometimes my bowels are normal other times they are lose and skinny (also smell very bad). My stomach sometimes fills full after just taking a few bites of a sandwich or eating something small. I feel bloated and gassy (Also stomach becomes hard). I feel full like can't eat anything else. Then sometimes I feel as if in my chest. I can taste my food in my throat and feel like I am going to vomit. I can be normal a day or two then feel like this a couple of times.