Shortness of breath while eating?

Hi all, out of the blue, I've developed shortness of breath while eating or shortly thereafter, going on for about a week now. The last few nights I can "feel" my heart thumps, but when I use an O2 pulse ox at home, pulse and saturation are normal. What could cause this?

I'm also curious, what are the symptoms of takotsubo syndrome? Is chest pain always present?

Thank you!