I usually sleep with my boxers only. And very many times it happens that when I wake up Im really messed up with my nose, eyes, mouth and throat. Like I have my eyes covered with some very dry things on them as if I cried and there are small solid pieces like tiny rocks that I have to try not to lead into the eye. And the throat is often suffering and I need to "puke" (I don't know the word for it) that thing you pull out making that sound like if you need to scratch the throat to get it out.
But especially my nose gets really dry and I wake up breathing from the mouth.
I found out that if I only wear a shirt when sleeping most of the problems won't show up but since I never proved this only happens when its cold, what could this thing be?
Since we're at it let me just ask this too. Why am I more relaxed and satisfied with less hours of sleep instead of many?

I don't think what you wear to bed has any bearing on your current problems. Possibly you need a humidifier in the room with you as the problems you mention are usually because the air is too dry that you are breathing while sleeping.

Sorry, don't know the answer to your last question.

Tick

Air too dry and probably too warm too. Winter air is extremely dry and most heat types make it dryer. Turn the heat way down at night and sleep under many blankets instead. Buy a $10 humidifier and put a tiny pinch of salt in the water.
Sleeping too much does make you sleepier. You need to be moving to get fresh oxygen to your cells and to get rid of carbon dioxide.

The word for "puke" is vomit... and I think you should get a humidifier to stop dryness of your nose. This probably has nothing to do with wearing your shirt at night. And if you can't get a humidifier, open some windows so you can breathe whilst you sleep. :-)