How do I drink less caffeine if....

Ap
How do I drink less caffeine if the only thing that calms my stomach is Dr pepper. Water makes me sick (including flavored), juice (fruit, artificially flavored, and stuff like orange juice) upsets my stomach and bowel movements, ginger ale makes me very gassy, Fanta sodas make me vomit.... I feel helpless because I know dark soda, caffeine, and sugar is bad for the baby but it's the only thing I can put down and keep down drinkwise