I have had the same trouble, I have been on a gluten-free diet and diagnosed as well 3 years. Just last night we went out with some friends for mexican food at the same place we have eaten at before. Well I had a chicken enchilada with I thought was a cheese sauce. It turned out to be a white sauce which probably had flour in it. I stayed home from work today because I had to make several trips to the restroom and had crampa badly. NOw I'm doing ok!
With celiac a weak positive is still a positive. It means you need to be completely gluten-free.
While it's certainly possible you're reacting more this time because of the recent virus, it also sounds like you were over it if you did fine during the holidays. The other possibility is that you're now getting more and more sensitive to gluten, which happens to some people when they go gluten-free. If this is the case, you will pay like this -- or even worse -- every time you eat gluten.