@mikegyi You have to indicate from your mastodon.social account that you've moved to Tootworks and remove that indication from the tootworks account.
As for the _1 added to your username, it happens with some accounts. And I'm not sure why. I suppose a race condition at the creation of the account and Mastodon already thinks there is an existing mikegyi account and appends _1 to create a new one. But it's pure speculation. Unfortunately, we can't change that.