Thanks for replying everyone
So... the meal was a hamburger with fries and a soda, pretty classic.
It is true I have become a vegetarian and this was the first meat I ate in months. I also excersize daily 10 miles on my home-bike, 40 sit-ups and 10 minutes weight lifting.
By the way they did count my electrolytes on the bloodtest and everything was perfect, as in right smack in the middle of normal. I also take a vegetarian vitamin & minerals supplement daily since I stopped eating meat, since I knew it would be hard to keep up with iron and B12 very well.
Also my blood pressure is ok. I check it personaly every other day and the hospital did so too.
My diet is pretty much 2 fruit a day, 3 portions of veggies, two portions of something with carbs (noodles, rice, bread all as brown as possible), 3 portions of low fat milk products and one egg. I only drink water and once in a while sugarless juice.
What I don't add at all to my food is salt and oils/butters. I thought the egg fat and the cheese fat was enough, since low fat dairy still has about 16-20% fat content.
Do you think it actually could be salt or fat missing in my diet?
I know it might not have been the meal, but my only symptom was this terrible drowziness. No coughs, sneezes, fevers or anything. I didn't miss sleep since I sleep 10 hours per day usually. So the meal was pretty much the only thing that changed.
I immediately went back to my diet since that night and today I started to feel drowzy again.
I think I'll go get my hormones checked. It is the only thing they could not check on the bloodtest at the hospital.
I hope it is the diet... I could easily fit more fat/salt or whatever within my 1800 calories, but hormones would be bad news...