Extreme tiredness, shivers, numbness after any meal during the day (even small portions)

20M, no known history of chronic diseases (though I never had any proper tests for diabetes or anything similar). I don't exercise much beyond 1h of jogging a few days a week. I am working on computer indoors for most of the day. No medication beyond supplements (Mg, Omega3, vitamin D, B complex). 185cm, 80kg, caucasian. For the last few years, I struggle with eating, where any food during roughly noon/afternoon makes me immensely tired and shivering. In my case, it can easily knock me out for **2-3 hours** or more. It is very limiting, because this way I can easily be productive for only half a day before I eat and some time after. The symptoms I experience are always: * Tiredness even despite having a good amount of quality sleep (9-10 hours) * Feeling of cold and having shivers down my spine; especially my fingers and feet feel cold even if I am covered in blankets until I am tired no more * My fingers usually feel numb and I get paresthesia (tingling) in them, my movements become a little more sluggish; in general my muscles feel both twitchy and weak/numb * Not initially, but after about 10 minutes of feeling the symptoms, I start to feel like my heart starts beating very strongly; that being said, my sugar and blood pressure seem normal even when experiencing the symptoms * It always takes about an hour before the symptoms kick in; I haven't found any specific meal that has better or worse effects, it seems to involve any meal, no matter how small the dosage - now I had 0.25l of garlic soup that knocked me out for 1.5h * I don't seem to have these problems when eating right after waking up or before going to sleep in the evening. The only solution I found is not to eat at all during the day, and save the food for the evening * That being said, there are occasionally days when even eating large portions of food have no effects on me, but they usually do I've done some blood tests for this, and one time I had indication for thyroid hypofunction, but when repeating the test a few months later, it seemed normal. If you could point me in the right direction for what I should investigate (eating when it comes to diet or medical tests), I'd be very thankful. I am aware that it is not unusual to feel tired after a meal, but in my case it is quite extreme and occurs even if the meal is not particularly hard to digest or is too large.