I know lamisil helps with skin fungus.
I have skin problems, and they arrived after washing my hand frequently with a harsh hand-wash. It happened around the same time I started cutting out all carbs and doing the carnivore diet, so I changed soap to something very mild, started eating honey, and loads of it, and fruits/berries and cut back on meat.
The skin is significantly better, .
I know that fasting helps a lot as well, especially for a few days if manageable.
But last resort for me if it doesn't clear up is lamisil, but as you wrote, it is a gut issue, so you will only be hiding the symptoms that are trying to make you change your diet because your current diet is evidently bad/not working for you.
I skip all processed foods and vegetable oils, and dairy, and try to get enough sunlight each day.