Continue. It’s not even possible to lose that kind of muscle mass, that quickly, unless youre actually starving yourself. The most common reason for “skinnyfat” is loose skin. Sounds like you need to add muscle. The skin will rebound over time.
Congrats on the weight loss!
Normal weight on a chart isn’t the same as normal for you. If you are carrying a lot of body fat still, you might have more to lose. But maybe not.
You certainly can and should do some weight training. Ideally, you would want to build strength and muscle tone, even if you are not trying to bulk up.
You also have to be realistic in that not many of us can get to 8% bodyfat, nor should we try. But there is nothing wrong with building some muscle mass and get leaner too. It all depends on your goals and how committed you are.
Keep in mind too that the health benefits of IF or restricted time eating go beyond just weight loss, such as improving insulin resistance and response. The metabolic benefits are enormous.
Look up Dr. Jason Fung on YouTube. He is a source of great information on the how and why of IF.