Good for you for starting your weight loss journey :)
I don’t believe your plan is too extreme, but I would be cautious given that it’s your first water fast.
As long as you have a big excess of body fat, I think it’s a good idea to do longer term fasts and once you have a few pounds left to lose, just do calorie counting with a 500 calorie deficit. Use an online TDEE calculator to figure out you TDEE and subtract 500.
Again, be very careful and see how you feel throughout. If at any point you don’t feel too good it’s okay to stop the fast (though if you’re just hungry, battle through). Watch out for dehydration. If you exercise, you might lose a lot of water and pass out, so hydrate well.
Whenever you’re off the fast, keep the 500 calorie deficit. Keep counting your calories and start another long fast when you’re ready. This way, you lose weight throughout. Use something like myfitnesspal to count calories. It’s easy to think you don’t need it because you lose so much weight while fasting, but it’s important to build the discipline so that you’re not over eating when you’re off the fast.
Good that you got electrolytes. Make sure you’re supplementing in the correct ratio. Check the faq to confirm.
Also, I know that people say that coffee/tea/0 calorie stuff don’t technically break the fast, but they can make it much harder to fast. They create a dopamine rush because they’re stimulants, and a few hours later, you”ll have a crash and feel down. So I would use them sparingly and be aware of the crash that follows.
I really want to emphasize that fasting is great tool and everything, but make sure you’re not going back to eating crap and/or binging when you’re off the fast, otherwise you’ll be exactly where you started. If you just keep the same conditions that got you where you are now, you’ll be back to where you are now. I see this a lot with people who fast, including my past self: fast a few days, lose weight, go back to eating junk.
Not sure if you binge from time to time, but It’s also very easy to justify binging by telling yourself “I”ll just fast tomorrow”. If you ever binge, don’t fast right away. Wait a few days. Just eat your 500 calories deficit.
Lastly, do some strength training to conserve as much muscle and gain some. Lightly when you’re fasting and when off the fast, try your best. Otherwise you’ll just look skinny fat ( you look skinny when you wear clothes but when you look at yourself in the mirror, you see chunks of fat even though you’re at the right bmi).
These are a few tips that I learned over time. I hope it helps and it’s not too disorganized haha.