I think you need to eat more, especially as you transistion. I aim for 1700-2200 kcals daily. I'm thinking of cutting that to a more consistent 1700-1800 now, as I have stalled and still want to lose more, but starting off low will only ensure your body thinks its starving. Later on you canIF and do all those things, but you have a better shot at succeeding if you don't walk around hungry!
Easiest way to up your calories: macadamia nuts and spoonfuls of coconut oil/butter. Primal bark containing both with dark chocolate is also an easy way to up calories. Fatty fish etc also makes for lots of cals with a ton of nutrition with it.