You are getting some pretty good advice.
It's important not to dismiss tachycardia. I had an episode that went into cardiac artery spasm, causing a heart attack. It was triggered by the sulfite in a bowl of cereal with dried fruit. I have had to learn Valsalva maneuver (bearing down with abdominal muscles like going to toilet), also trying coughing. My cardiologist has me keep a few pills of atenolol on hand, and I also take a couple of aspirin when this starts. You did see a cardiologist, didn't you?
The blood test for celiac is sometimes innaccurate. The "gold standard" is the biopsy. But that's not much fun.
You can start new allergies or intolerances any time. Intolerances can build up from things you are eating or drinking. Beer has sulfite, but also gluten and wheat. Wheat intolerance is different from gluten intolerance. Allergy is different still!
The first thing to do is start keeping a food journal/log. Write down everything you eat and drink, all meds, the times. Then write down your reactions. Sulfite will usually cause tachycardia within a couple of hours. My reaction is usually about a half hour, but has been as long as 4 hours. Migraine sufferers can get reactions to sulfite as far out as 2 days.
When you find a list of foods or drinks that trigger your racing heart, google them with the words "food intolerances" or food allergies." That's how I found my whole list. There is no cure. If your problem really is sulfite, you'll have to give up the beer, wine, pizza, chocolate, etc. It can be life-threatening, as you can see from my heart attack! But don't assume this is your problem without checking for sure. There is no blood or skin test that is approved yet, and most doctors have never heard of sulfite intolerance, so you'll have to do it on your own.