It took you years to gain the weight, it wont come off in a week.
Stay in the game and aim for the long term, reduce your diet, adjust your diet, eat healthy, and fast occasionally not constantly to give your body a jump on the process.
Fasting is part of the process not the complete end all be all.
It is a bit surprising to me just based on results ive seen here. But, don’t give up. Don’t eat back all the calories.
Id give it another go, perhaps since this is your first time your body is holding onto the water/waste cause its like “Where the F did the food go?!” Id do a refeed whatever that looks like to you, day, 2 days, and get back to it.
Are you weighing yourself first thing in the morning? I would. I go pee, and then weigh myself. and make sure you use the same routine going forward. Don’t drink water, or anything in between.
The process you’ll need to think about is “Whatever I just did, I need to do this 10-20 times in a row” - So go 5-8 days, eat something sensible (don’t binge with like 2-3 entries, ask me how I know…), and then go another 4-5 days, or 5-8 days, and then do it again.