The fishy politics of mortals on planet Earth

I wish someone could explain in layman's terms why a country that should be rich because of all the oil they export is still in the grips of shortage of food,etc.  Is America and America's allies playing havoc with Venezuela's currency? Are the riches they gain by selling their oil in any given week, translate into less than half the next week because of the financial manipulation by bully powers?  Something smells to high heaven.... but being the dodo that I am, I can't figure it out.  The trouble there can't all be because the country's govt. is socialist.  If you believe that, you also believe in Santa Claus and Big Foot.

From ASCOA:
....February 26: Pro- and anti-government demonstrations take place in Caracas ahead of President Nicolás Maduro's "peace conference" with different sectors of society. The opposition Democratic Unity coalition says it will not participate in the conference, calling it a "simulation of a dialogue."

February 25: The United States expels three Venezuelan diplomats from the U.S. embassy in Washington, after Venezuela expelled three U.S. diplomats on February 16. A State Department representative says the U.S. government wants to see more "positive steps" from the Venezuelan government before it appoints an ambassador. However, the Venezuelan government goes ahead with the announcement of its new ambassador to the U.S. Foreign Minister Elías Jaua taps Maximilian Arveláez—a former ambassador to Brazil—for the position. Former U.S. President Jimmy Carter offers to mediate between the government and opposition on an upcoming April visit to Venezuela. U.S. Senator Marco Rubio says he plans to propose sanctions against Venezuela. Lilian Tintori, the wife of imprisoned opposition figure Leopoldo López, tells Chile's El Mercurio that López is in a 6.5 foot by 6.5 foot cell and though he is cut off from any communication, authorities are allowing family visits. The death toll rises to 15......