you admit your mistake with courage. even though you didn't admit it before, but making this thread and admitting your mistake, that's courage. or maybe I'm wrong, that's desperation?
Either way, I think it's the right thing to do. The next one would be to move on or wait for the reply.
Casinos have strict rules on violations same with every other platforms, and regardless wether you apologise or not, their have taken their decision a d if you ever get considered it could be that your offense is a minu offence but multiple accounting is something that most casinos kick against without any possible reversal of such penalties.
Any ways I hope you just move on with your life and try to stay away from committing such offence on other casinos aside from shuffle.