Game Progress Disappeared due to email update

HOw can I get all my game progess back? I had to change email addresses but still use same gamertag, why did all my game progress disappear and how can I get it back?

For most games you should only need to load then up again and play a game or 2 - Forge, Customs, Campaign, Multiplayer, everything should sync up again shortly afterwards. The only exception is likely going to be Halo 2 as the original XBL servers are offline now

I still don’t see all my progress. Is there a way to check if it is syncing with xbox?