Here's a chick whose channel is not a bad resource for figuring out an affordable way to eat lots of fatty animal foods. And if you can't manage that; rice and/or honey indeed. No set portions, just eat as much as it takes to stop feeling lethargic and if after a good while nothing works (either fat or carbs) I would advise you indeed just go to a doctor and get stuff like your thyroid checked.
We have very similar stories except I managed to really get into junk food around my pre-teen years and ballooned up almost to the point of obesity (long-story). I managed to get myself under control and drop 30kgs in like half a year at 14 (also long-story) but one useful side-effect regarding that was that eversince then I've had a pretty ravenous and robust appetite unlike when I was little and would need to be almost forced to eat.
I used to think so too but I think it's honestly every human population on Earth. We are all still walking around with paleolithic bodies that don't know what to do with things like refined sugar, all these grains and vegetables, seed oils and whatnot. Look no further than India... the homeland of all these spices, so many plant and grain-based foods and the homeland of vegetarianism as well and you'll see alarming rates of obesity, skinny-fat physiques, digestive issues, nutritional deficiencies, type-2 diabetes and so forth. The human capital of eating in these ways hasn't "adapted" to it either. It's all of us, abowe. We were never designed to eat this way as humans. Some just deteriorate worse than others.
