I used to get the same way. I am sure that few times trying something new I did not have a reaction but an anxiety attack over it hahahaha… I am getting a bit calmer now and feel more in the control after I actually had success introducing few things. After you introduce one or two items without trouble, your anxiety will go down a bit. Just do it smart. Every time I didn’t do it slowly I was sorry for one reason or another, but regardless you need to do it carefully and space out new items at least a week apart to be able to tell if you react or get any symptoms back.
Good luck and let us know how it goes!