Hi
@jonnytaxi you are more than halfway to where you want to get to as your enthusiasium (mindset) is great.
I used to hit the wall (bonk) during a 3 mile intensive walk along Walton on the Naze, would get home and have some fish protein to feel better. I now know I was not fully fat adapted. By way of example last evening along the same route I did 5 miles 1.5 hours after a 16.00 dinner (with 10 x 2 bicep curls dumbbells I carried in the boot); this morning I did a further 5.15 miles. So that is 10 miles without food, and I will do intensive heavy weights before a meal circa 16.00. I detail this to show the amazing things that fat adaptation can do.
My method was to move away from low GI what I believe is termed as clean eating, e.g. at the time home made soda bread with mackerel/ salmon, sweet potatoes in place of regular potatoes / rice / pasta. I cautiously switched from low fat yogurt to full fat, included hard cheese (my favourite being black bomber), kicked out all vegetable oils and replaced with olive, coconut and avocado oils. Included avocados, nuts and seeds.
I can say, this transformed my energy levels, improved my HbA1c, reduced my visceral fat and thereby leaned me up.
I continue to tweak, so have been experimenting with fresh coconut water, blending a slow roasting the coconut meat (I prefer making my own desiccated) and coconut milk here and there, as well as cooking where possible with MCT oil. I don't go mad, as I am also biasing towards some additional protein (liver), often doing surf and turf with low GI veggies.