Your own store gets built alongside your Etsy shop, not instead of it. Your Etsy listings stay exactly as they are: same photos, same titles, same reviews, still selling. The only thing the two shops share is stock counts, so a sale in one place updates the other.
When the new store is ready, it goes live at your own domain and you have a second place to sell this season, one with no listing fees and no other shops' ads next to your work.
Rather wait until things are quiet? Book now and we do it in January.