I’m sorry to hear that you are experiencing these reactions. Now, I am by no means an expert, but I would suspect that perhaps your gut flora have been altered as a result of your paleo diet experience, and are not currently able to processes such foods as a result – currently. Whether this is permanent or only temporary I can’t say for sure, but I believe that you should see some improvement as time progresses. I had an issue like this for awhile once I incorporated carbs back into my diet, but the symptoms weren’t as drastic as yours seem to be.
Best of luck