So, I was on the phone debugging the problem with OVH and we were able to bring the instance back online.
This caused the service to be partially down (because host 1 was still running for anyone that was using that DNS configuration) for a little over an hour.
Really sorry about the trouble this might have caused.
Traffic grew 10x in one week and it was impossible for me to predict (or afford) to scale for this before it happened.
Hope you understand.
@mastohost All good from my little server! Thanks for fixing it so quickly. Interest in Mastodon grew so rapidly you have no time to prepare. Go well!