my body is acting stupid right now

so i was super hungry like 30 mins ago so i went downstairs and got some chips and cheese.. Now i’m feeling nauseous ! again!!! this has been happening for quite sometime.. well like 3 or 4 days now. Im not pregnant because my period doesn’t start til 2 more weeks. Idk what’s wrong with me.. I do have acid reflux but it’s not it . it’s something else .. I’m trying to gain weight too but it’s not happening because of my nausea. i rather would do diarrhea than throwing up. I HATE THROWING UP ! it’s my phobia .