How odd. I drink tea all the time and it never upsets my stomach. Green tea is actually anti-bacterial.
Are you making it too strong, or mixing it with other "uppers" like nicotene?
"Sentiment without action is the ruin of the soul." - Edward Abbey
"In those days I, Daniel, was mourning three full weeks. I ate no pleasant food, no meat or wine came into my mouth, nor did I anoint myself at all, till three whole weeks were fulfilled." Daniel 10:2-3