Hello Claire -
What you describe sounds most like a spasm or stricture of the esophagus. It could be something else, but since it is triggered by swallowing food it most sounds like an esophageal problem. Rarely, however, and especially in women, heart problems can present themselves in very atypical fashion, and while such a thing is extremely unlikely, I'd be remiss if I didn't mention that this should re ruled out. It really seems most likely a spasm of the esophagus (a stricture shouln't show up so abruptly; spasm can start any time). Either esophageal problem could be treated with oral medication and possibly some dietary caution.
if it weren't for that "band of
pain." That's what makes me feel a heart problem, however unlikely, should be ruled out, and this should be easy to do. Then you might be prescribed something for what is very likely an esophageal problem.
I hope this is helpful to you. Please follow up here as necessary.