Jack...you need to dig a little deeper when you return to Cuba.
As with many others here, I have traveled extensively, both for pleasure and for business. I agree with some on the opinions here that you saw exactly what you were expected to see. Talked to whom you were allowed to talk to, visit places you were supposed to visit and garner opinions that you were supposed to hear.
It is a very experienced communist country that has kept its secrets extremely well for the better part of 50 years. It's not some James Bond movie where espionage lurks at each corner. But the country has been very well controlled and people have been well supressed for a couple generations.
Can people speak freely with you? Nope. Will they....just because you speak Spanish? No. Is the typical person on the street willing to say anything against Cuba or Castro or their way of life to a total stranger...regardless of the reason for your visit...no.
You see...no one knows you there. You say that you have family in Central America. You should be well aware that trust does not come cheap, nor is freely given in that particular society. It is earned, over time. If you are a Gringo like me, then that trust may take months or years. It is admirable that you spent 3 weeks in Cuba. Many of us may never get to visit Cuba.
Those of us who have traveled, and have spent extended time in various countries, know that there is much more to be seen and discovered than 3 weeks allows for.
Having a positive opinion or to say things aren't so bad in Cuba, shows that you need more time there, or maybe spend more time with Cuban exiles to get a true..less rosey...picture.