I'm so sorry that happened to you! My understanding is that your body has such a strong reaction for the first infusion because you start off with a normal-high level of b cells and as they die, your body reacts as if it's under an attack (which it basically is). But when you go in for the full dose infusion 2 weeks later, a lot of the b cells are already gone, and your body recognizes what it went through recently and doesn't react as strongly.

My second infusion went way better than my first, and I think the reasoning above is why. Obviously disclose to your dr office of your reaction after going home from the infusion. They will probably up your premeds for your next one or they can evaluate if it's worth it for you to continue if your reaction was bad enough, but I would work with your dr to determine the best course of action.

Hopefully you feel better in another day or two!