Have you ever lost 21 lbs in just over a month? You're absolutely on track.
My surgery was also on October 17th. I've lost around 27 lbs. 5'6- starting weight was 227 day of surgery.
The absolute worst thing you can. Do to yourself is compare your journey to others.
This surgery isn't a quick fix. You will have slow loss some months and seemingly easy months with fast loss.
Trust the process. Don't get frustrated abd just focus on what you can control. Nutrition and Water. Everything else will follow.