No...youre throat is not closing but it is constricting, its very common. Youre voice might also get a lil high pitched too if youre one of those type of people but you wont choke if thats what youre thinking so there isnt a reason too be scared. You could try to cool the smoke down in a ice-filled bong or something but other than that there really isnt alot you can do about it except maybe ingesting it a different way. I have to recommend eating it....the high is smoother...comes on a lil slow and then hits really nice and mellow and no more choke throat....
Ever since i got a pipe ( two weeks ago), ive got this throat feeling too. didnt happen with joints. Maybe its the pipe thats doing it, or the different source of weed i also had. caus i tried a mix of the throat-bad and some other stuff, and it was less. but yeah, i was freaked out about it as well, thinkning i was ahving toruble breathing. but then i stopped and actually thought about it, testing air flow and breath, and i found, my through was barely constricted at all, it was jsut the nerves playing up. it obviosuly was a tiny bit inflamed but i was smoking plain weed of course. so overall, i came across the same situation, but not im used to it.