Nigeria reach a server in Hetzner Germany over a route that's already reasonable — Europe is the closest well-connected hub to West Africa, and most African internet traffic routes through Europe anyway. If you moved the server to Oregon, every one of your users' requests would cross the Atlantic, making the whole app slower for everyone. That's the wrong direction.
The actual problem is purely your server→database link: Germany → Oregon, ~160ms per query. Fix that by putting the database in Europe, close to your server. Then:
