I’m not a fan of 5:2, if you mean the 5:2 diet where you eat whatever you want whenever you want for 5 days and then spend 2 days eating 500 calories. This does not work well if you have problems overeating or eat a lot of sugar/high carb. You can do so much damage in 5 days that 2 days of low calories cannot overcome. And those 2 days will be absolutely miserable. 18:6 is much better, and you will see the best results if you can lengthen your fasting window and get to OMAD and extended fasts.
Daily habits are easier to build and maintain. 5:2 is not going to have as good a long term effect on your relationship with eating, so you might rebound from your goal weight if you stop once you get there. A constant 16:8 or 18:6 will be sustainable and also help form your internal food clock to reduce hunger and urges overall, because you get your stomach used to less food at certain times of day.
Do not focus on the speed of your loss, just focus on the healthy changes and sticking to your habit.