>>Still wondering how the embargo caused Cuba's poverty.

Here's a declassified State Department memo from 1960 advocating policies to be "as adroit and inconspicuous as possible, [while making] the greatest inroads in denying money and supplies to Cuba, to decrease monetary and real wages, to bring about hunger, desperation and overthrow of government." https://history.state.gov/historicaldocuments/frus1958-60v06/d499

There's plenty more, e.g. the Helms-Burton Act threatening punishments for foreign individuals or companies that dare to trade with Cuba. https://en.wikipedia.org/wiki/Helms%E2%80%93Burton_Act This determination to extend US authority extra-territorially to pursue this obsession with Cuba has caused international exasperation- e.g. in Canada where a lampooning Godfrey-Milliken bill demanded the return of Loyalist property seized by the American government after the American Revolution.