Hey Makeitreal! You know what? That's actuallynot too wide an age gap. And if you think about it, the only person whose opinions matter is yourself. If, from the bottom of your heart, you believe that there's nothing wrong with your relationship or with your man, noone has the right to try and make you change your mind. Your brother can sulk or yell or threaten all he wants. It's not his life he's trying to ruin but yours. I hope you never have to choose between the family you grew up with and the man you'd like to spend your life with. But if push comes to shove, just remember that you're an adult and your brother's gonna have to learn to treat you like one.
I don't think you should keep trying to explain to your brother. It sounds like you've tried a few times already and it may be like talking to a brick wall. You'll just have to show him how happy you are. It may be time to let actions speak louder than words. If your brother didn't give your man a chance when they met face to face, he's not gonna do it now that he's far away.
I'm sure your brother means well, but it's high time he allow you to be the adult that you are. That's something a lot of Filipinos/Filipinas have a tough time swallowing. We're all raised to put our family's opinions first. But if you live your life choosing what they want for you instead of what you want for yourself, you're never gonna be happy. Besides, all that matters is that you found a good man, right? He's loving, supportive, doesn't mind that you've got a kid already, is willing to follow you to the ends of the earth (or to the Philippines, at least), wants to learn more about your culture, and he tried his hardest to get your family to like him. Don't you think you deserve that kind of man?
I hope your brother comes around soon.