Could My Nausea After Rice, Palpitations After Pizza, And Sensitivity To Caffeine Be Caused By Something Other Than Anxiety Or Stress?

I have noticed that i get a little nauseous after I have rice. Mostly cooked rice. And I ve also noticed palpitations after I have pizza even though I eat other heavy and fried foods and have zero to no discomfort. i sometimes have migraines too but they re mostly mild. Other than that I m quite sensitive to caffeine too it makes me very anxious and causes palpitations. Both of the general physicians I went to said it was all anxiety and stress and depression related. Which might be the case since I ve been through a number of traumatic experiences. Also I m 18 and a female. and underweight too.