Gnawing Pain

The same thing is happening to me right now. It's been 5 days and my stomach is gnawing and I get sharp pains penetrating to my back and I feel nauseous at times. I don't know whats wrong with me.

I'm fourteen and i've been getting stomach pains at complete random on and off for almost a year. There's no pattern to the intensity of the pain, or when the pain occurs. Sometimes I get it early in the morning, at like 9 or 10 (i wake up at 6), right before lunch, or in the evening or late at night. Sometimes the pain is just a dull-ish ache, sometimes a deep biting pain, sometimes a painful nuesia, and the pains offten make me want to curl up into a ball. I've vomited at random, and when I do I usually taste strong stomach acids (stronger than if I just have the flu or such). I've been having odd tastes in my mouth also-really sweet and sugary, bloody and metallic, acidic-with out consuming any thing to cause these tastes, and sometimes almost like smell blood from the back of my throat.

I have a bit of a caffeine habit-i drink coffee all day, lots of energy drinks, sometimes caffiene pills. I do not know if this is at all related to caffeine or what.