No god would condemn anyone for being happy. Even if the priest is of the Christian faith (you didn't mention that), it is taught that all people are loved by god regardless.
I think you should do what makes you happy. I understand your unhappiness. It sounds like you've been trapped in an unhappy relationship for years and you're in genuine love with someone else who makes you happy. But there are many cultural (and religious) hexes on this. It's difficult sorting all this out, especially with children in the picture. I would tread lightly, and try to give yourself a break. Is the reason you're not considering because of your children, because of their feelings about it, or because you're afraid you won't be able to afford it?
I hope everything works out for you.