How long have you been doing one meal a day? That in itself is a great accomplishment and is called OMAD (One Meal A Day). Keep doing that and you will be seeing major improvements in weight and health.
Practice makes perfect, meaning it gets much easier the more experience you have with fasting. Something to help would be home made bone broth, or you can mix up water, apple cider vinegar, salt and a pinch of lemon to serve as an electrolyte drink. I’ve heard of some people drinking kombucha too.