You are not alone in these feelings, friend.

It seems like you might've posted on the wrong sub, so sorry if my thoughts here are unwanted, but:

If you want to change your weight permanently, you need to change your lifestyle permanently. I would think long and hard about if fasting really works for you. Is it really something you can do for the rest of your life?

Cardio is excellent, but the calories burned can be undone all too easily by eating the wrong foods or too much food.

Obviously I like the Weightwatchers program or I wouldn't be here, but if it doesn't sound like your thing you should also look into CICO (calories in, calories out) or the Mediterranean diet, imo. Something that helps you learn about food and nutrition and is not about just temporarily cutting back. Make it a goal to build good habits.

CICO in particular will quantifiably help you stop from undoing your cardio efforts. Weightwatchers should work fine for that goal too.