OCD fear *TRIGGER WARNING*

Hi, I have a serious fear of chemicals. I have a constant nagging thought that I might ingest some chemicals that will give me brain damage or nerve damage. Now, it's recently got a lot worse. Say if someone sprayed deoderant, I'd have to constantly hack up phlegm until the smell is gone, but, with that, hacking up phlegm makes your eyes and nose shake, which makes me more paranoid, thinking that I may cause a brain hemorrhage from the shaking or damage my brain in some way. I just had a bad episode with this so I need to write it down to calm down a bit. I do this in the shower too, with soap smells, but I have taught myself not to do it as much in the shower.

I just need some closure with this. Anyone else gone through this kind of thing? Replies would be greatly appreciated.