Intermittent Fasting and Caloric Restriction

Hey there women of xxfasting. Booted up an old diet account to ask this question anonymously... I've been doing intermittent fasting without restricting calories for about 3 months (not perfectly, but more days than not) and I've really been enjoying the benefits in my energy levels, mental clarity, and body composition shifts. My weight is relatively stable---I've lost perhaps 5 lbs, but seen a lot of shifts in muscle mass that I really like. I consistently do strength training right at the end of my fasting window. I tend to eat between 7 PM and Midnight. Yesterday, for the first time, I intentionally cut back my calories to 1200 (maintenance for me is around 1900), and I feel pretty wrecked today. Headachy, lack of focus, pretty low willpower. It happened so suddenly and so intensely that I feel like this degree of calorie restriction isn't appropriate for me, and it makes me sad for all of the years in my teens and early 20s when I'd regularly be on diets this restrictive--it feels awful. I think I'll stick it out until my usual eating window just for the sake of my confidence, but I think I'll need a more moderate cut, especially if I'm going to continue stregth training. Perhaps people adapt to this level of calorie restriction, but it's hard for me to see how I'd be able to function on this level of impairment for more than a few days. Anyone relate? Anyone have suggestions? I've considered possibilities like a bone broth modification, but I like the autophagia benefits of IF the most (it's been great for reducing my chronic joint pain).