Coffee does affect me quite a bit if I drink too much. Lately I just quit drinking it becaue I thought it would be contributing to anxiety. it probably has but I still have still had anxiety or some sort of edginess, uneasiness, "excited/hot" feelings, jumpiness, rapid heartbeat even without it. I also think the coffee roast and type of coffee might change the feel of the coffee, or the way it's made. Yerba mate is supposed to have a "cleaner" type of caffeine which doesn't give the gitters as much as coffee.
there might be some good alternatives though.