Hi there ~ symptoms such as yours i.e. eating something and subsequently having cramps, having a sickly feel, shakiness and blurred vision
seem to me like they are related to a gastrointestinal condition. Feeling of passing out or passing out after food also needs medical attention. I suggest that you see a gastrointestinal (GI) physician. However, if it is stress
and you need to elaborate on the kind of stress please feel free to do so here, I may have answers for you. Alternatively, speak with a psychiatrist
about your stressors. I hope this helps. Take care and have a good day !