I've barely contributed to this thread but today I overcame a big block for me - i threw up!
I've always had a phobia of choking and being sick but I did not have much choice today as I seem to have food poisoning.
It was quite possibly the most horrible experience of my life -couldn't breathe /hyper(o?)ventilating, couldn't move and had my first proper panic attack in 10 years. Weirdly my hands completely locked up and I could not move my fingers at all for about 15 mins.
Throwing up because of food poisoning is one of the worst types of throwing up, because it can just go on and on till you're retching nothing but stomach acid.
It sounds weird, but when throwing up like this, or if it happens again, try to relax. Like in most situations, the more relaxed you can be, the more in control you are and, in this case, you reduce the risk of choking.
Anyway, it seems you're a bit better now so that's good.