But at this point what we can do?, we have to keep trying, we love each other so much, this is a really sad day for both of us, and what bothers me is the way they are treating people at the interview, is not fair, there is not need for that kind of attitude towards people.
Thanks so much for your reply, I really don't know what a red flag is. 
Red flags are a "checklist" of common traits or elements that may trigger suspicion of immigration fraud.
Answer the following questions: (not here, just for your information)
Age gap/ difference?
Do you make enough money to sponsor him?
How many times have you visited? The revolution is no excuse. I went there 3 times during the revolution.
Do you have children? ages?
Previous marriages/ divorces (for both of you)?
What are your educational backgrounds?
Has he wired transferred money to you?
Have you sent money to him?
Religious differences? If not, did she convert upon your request?
Language barriers?
How did you meet? Internet? common friends and family?
Did you meet his family and friends?
Did he bring any proof of a bonafide relationship? What were those items?
Does he have family and friends in the US?
Has he been petitioned before?
The only way we can help you is if you answer these questions AND you give us a detailed account of the interview. Other than that, getting married will NOT guarantee approval. You must address all this, find out why he was denied and then decide what actions to take.
Good luck!
Don't ever do anything you're not willing to explain the paramedics.