What kind of a respirator?
Different people refer to "respirator" differently. To some it is a face (nose/mouth) mask with a couple of small exhaust ports, while others refer to ones with replaceable filters.
Your post sounds like you are highly sensitive to CA, and I am too. If you are extremely sensitive, you may need eye goggles as well. Don't fool around with that. You also may be sensitive to deer antler dust, but in most probability, it is the CA.
I turned pens for two years with no problems and then one day, I got the sniffles. A few days later, I turned another pen and got flu like symptoms. The third time was a charm with double vision with the flu like symptoms. I stopped until I got the respirator, DC filter, face mask and fan blowing across the lathe. No problems since.
I mentioned my experience because it seems like you may have turned and used CA before and are just now experiencing the symptoms. It doesn't always start at the beginning, but later on.