I usually drink coffee in the morning, but today I didn't have any 'cause I was in a hurry. I felt depressed all day and couldn't stop crying. There were little things that I was sad about, but nothing that big that could really make me cry like this. Could this have been from my lack of caffeine?

I have trouble sleeping at night so I get the most sleep that I can (about 7 hours), but by the morning and throughout the day I am wiped out. I drink a cup of coffee in the morning and then at least one mountain dew during the day. I don't want to take in that much caffeine, any suggestions on other options I could use?

I drink three cups of coffee in the morning and a couple of diet pepsi's in the afternoon. How much caffeine am I taking in? How much is too much?

I usually have 2-3 cups of coffee in the morning and a large glass of ice-tea in the afternoon. My doctor advised me to reduce my caffeine intake. I have been making 1/2 decaf and 1/2 regular coffee (mix) but I'm getting headaches.
Any tips on how to reduce my caffeine intake?
What is a good cold drink to replace my afternoon ice-tea?

Any tips will be greatly appreciated.