I'm male, 53, 5'11" so very similar.
I walk 6km per day, 5 days a week and paddle about 10km most weekends. No other working out. I eat a shed load more than that. My weight is steady at 73 kg
Suggest you look at the following:
* getting enough sleep
* reducing stress - this may include reducing your workouts. Replace them with play or something more meditative
* eating more - if you're starving yourself and very active your body will go into starvation mode. Particularly if you're not getting enough protein. You should be getting around 150g a day. Are you? Not by the sound of that menu
Four years Primal with influences from Jaminet & Shanahan and a focus on being anti-inflammatory. Using Primal to treat CVD and prevent stents from blocking free of drugs.
Eat creatures nose-to-tail (animal, fowl, fish, crustacea, molluscs), a large variety of vegetables (raw, cooked and fermented, including safe starches), dairy (cheese & yoghurt), occasional fruit, cocoa, turmeric & red wine