It could simply be the amount of fluid. If you're not used to drinking a half-gallon of anything when training, that takes some getting used to. Play around with spacing it out more - drink the pre-training amount a little longer before going to the gym, have a little less during the session, and wait a while after to finish it.
Or, if you know you don't do well with creatine, there's no creatine monohydrate in it, but try reducing the Anaconda to just one scoop. Anaconda has a different type of creatine.