You just have to get used to it. The vapor is a lot different then cigarette smoke. It took me about three or four days. At first, I couldn't even bring the vape in without completely gagging. Then after a while, I was able to inhale more vape. Now I'm vaping 24MG like a boss.
I tried this before and the choking scared me away. I tried different things that people suggested like a lower nic level, higher VG, etc. All I ended up with was some useless 12mg juice I paid a lot for that sits in a bin as I blend it with a higher nic level, little at a time. I'm glad I gave it another go.
If you are smoking, try and stop since cigarette smoke irritates your throat which also could be an issue.
Also, don't hit it like a cigarette. Bring the vape into your mouth with a slow draw. Then bring it into your lungs. You also don't have to. You still get nicotine from your mouth and nose. You can gradually try bigger inhales. Eventually, choking shouldn't be an issue.
And what kind of equipment are you using? Some of these tanks can be very harsh on newcomers. I learned that the hard way with this Vivi Nova I had.