Good for you!
Now I think you may need to take it one step further. You referred to an "affair". My understanding of this word is that it is a secondary and usually temporary relationship; an act of infidelity to the spouse or significant other. Unless this "affair" was with another foreign woman he met after you, it is is highly unlikely this was the case. Face it honey, if he has a Dominican girlfriend, you at best were the affair, and more likely not even that, but merely a potential ticket to the promised land. Accept that, and you will be really ready to move on.
It is possible that your situation was the "exception", and I'm sure if it was you'll let us know.