why do i feel all perky during the day and depressed @ night?

cuz u drink coffee, retard. you said it yourself.

coffee (aka caffeine) has many bad and persistent side effects, including a crash, irritability, trouble sleeping or concentrating, lowered athletic performance and lifespan in the long run, worse skin and hair, depression, mood swings, the jitters, insomnia, lowered IQ, headaches, migraines, and heart attacks.

You are experiencing "the crash" and this is causing you to get tired, depressed, and irritable- as well as having too many thoughts and too little sleep!

You should switch coffee with THIS BREAKFAST: (breakfast helps you lose weight and be more athletic and energetic, btw)

2 eggs over easy

a protein shake

Kashi cereal (or another healthy cereal) with ORGANIC WHOLE MILK

orange, cranberry, or apple juice

You will eat a little less during the day, and you will have energy, and since this is food, NOT a dangerous drug, YOU WILL NOT HAVE A CRASH WHEN THE FOOD IS USED UP- YOU WILL SIMPLY BECOME HUNGRY AGAIN!

Probably due to the melatonin your brain releases in response to the circadian rhythm. During the day, you have less melatonin in your bloodstream (if any), however, the more hours that pass from your last "sleep time," melatonin levels increase and make you more tired. This of course, affects your brain chemistry and the way your emotions react to everything. And, being tired usually makes a person irritable.

You also said that you had one hour less of sleep. By making any change in your sleep schedule, you mess with the melatonin release and cause it to be sent into the bloodstream earlier and in higher concentration. Try to sleep more hours, and if you can; cut down on the coffee. Coffee is a stimulant which also causes irritability especially when you crash. Drink more juice with vitamins, like OJ or apple juice. In fact, apple juice is a better "upper" in the morning than coffee and should help out your physiology more.

we revolove around the sun!

when sunlight come through out eyes we produce chemicals that keeps us awake!

chemical changes in your body and brain.