I’d say keep a journal and mark down your energy level and emotional state.
If they starts to slide (which usually leads to rebound) - try to up the calories.
Might be useful to check your ketones especially morning after the lower calorie days and/or invest into CGM.
You can add extra virgin olive oil, nuts, and seeds. It’ll hike up your kcal healthy way and you will not feel much difference in volume of your meal. It’s high density foods.
Count your TDEE, and as a male, don’t eat less than 1500kcal a day.
I’ve never been a calorie counter, and would encourage you to listen to your body.
Appetite is hormonally managed, it’s very complex, but it’s strongly affected by what (and when) you eat. An oversimplification is eat high glycemic index foods, your BG goes up, your insulin goes up, BG gets stored as fat in adipose tissue, and appetite increases to replenish. This is bad, so eat low glycemic index foods (typically whole foods), and your hormones will work better and not cause unnecessary hunger.
If you’re in this for the long haul, I’d encourage you to build good habits. Eat good foods. This will keep your hormones working well. Learn to listen to your hunger. I’m skeptical that most people can measure their food and count calories for decades, in opposition to their senses.