It is really surprising to see a player in Mythic age, having his opponent in Classical age, to lose the game. He has more than 20000 food and 1000s of other resource when lost... it is really hard to believe. I think your brother is an amateur.
But your recovery was great. You had 0 gold at an instance but recovered. You could have made use of markets to bring gold... anyhow your recovery and confidence was great to see.