Sickness after lunch

Hi, I have had this problem for more than 3 months now. I feel sick after having lunch. Mostly I eat rice and some curry with vegetables and very less of spices. I am accustomed to spices since I was a kid and never had a problem with it in the past. But I have noticed lately that I become nauseous and feel that my head is getting heavier. I sometimes feel weird in my eyes too. I drink lots of water before and after food yet I continue to feel so even after hours of having lunch. I had my abdomen ultrasound done in November and they said that I have no issues with any of my digestive organs. If i have class or work after lunch, my concentration falls drastically and I have difficulty maintaining my mental balance. I have tried switching to seeds and nuts instead of rice and curry and have also tried light pure vegetable sandwiches but in vain. It does not happen in breakfast (cereals and milk, 3 sugar cookies) and dinner (4 slices of bread and rice with some curry and vegetables) also passes quickly without me even realising that i have had dinner but lunch seems to be the only issue here. Please could you guide me why  does that happen to me. Thank you!!!

[frootbar]

could be a bunch of things.
if you take meds, drink alcohol, smoke, these can all be factors.
you could have h/pylori infection, or not.
you seem to eat too much bread, sugar cookies are ****.
what about stress at work?  what about any stress?  you
should search your mind for all possible things that could upset one's
stomach, be it emotional or physical/internal, and see if you can
make sense of anything.
asking the doc for an h/pylori test and a blood film would be a start.

frootbar C.N.