I can't be around any perfume, smoke, or cleaning agents. Also, sometimes people in a store will use perfumed lotion and I have to put the bag in the trunk to take it home. My pain is at the back of my head at the bottom next to my neck. First I notice swelling of my nostrils and then the pain. I have learned to get away from any smells and manage to do very well dodging them. I use citra-dish to wash dishes. I use soda and vinegar for cleaning. One time my daughter had company that had perfume on and I went out on the deck to get away from it and forgot that the termite sprayers had been there. They think they are doing us a favor by getting rid of the smell but when it has a smell, you know when to run. I had to go to bed with vertigo that time. I have MCS(multiple chemical sensitivity) and I suspect that you do too. I imagine that the first incident you experienced caused yours and now you will have to stay from all chemicals. I also have electromagnetic hypersensitivity and cannot use a Cell Phone or be around wifi. One of the worst chemicals is in dryer sheets. The MCS is easier to avoid the culprits than EHS, so be careful. I'm pretty sure mine was caused by mercury toxicity. I hope this helps. NB