What you're describing almost sounds like an allergic reaction. Do you have allergies? Have you eaten or taken anything new that you may be allergic to?
I had my Nissen about 3 and a half years ago, and while there were certainly quirks that lasted a year or longer (that finally settled down), I don't remember ever having the symptoms you've described in relation to my recovery.
I do have allergies and can have throat and breathing issues for that reason.
Wish I could help you more! Hopefully somebody will be by soon with additional comments.
Very best wishes! I hope you feel better soon,