I'm 37 and after gaining a lot of fat and losing a lot of muscle following a 3 month nigh immobile period, due to a severe spinal injury, I am now down 41lbs in under 4 months to 194 at 6'2", making me only just nominal BMI and 25% body fat per the navy method. I plateaued at 195 because my metabolism ground to a halt for 3 weeks, I was cold all the time, lost intensity in my workouts, and had to do a 1 week maintenance diet break to pull out of that slump, which has prompted me to refocus from losing weight to a mindset of gaining muscle while losing fat.

I'm in the process of switching gears from a steep cut of 1600 kcal, minimum 150g of protein, with 2 days on 1 day off of moderate resistance band training incorporating 2 sets for 13 exercises (~40-60min of effort) and 15 min at 14-15mph on a stationary bike daily with up to 45min on the off days, to a more body recomposition friendly flexible 1850-2250 kcal diet range (still weighing food and cooking almost exclusively at home for accuracy), planning a 2500 kcal diet break every 4th week, and increasing my resistance training from 2 to 3 sets (~60-80 min of effort) but every other day and doubling my biking volume to 30m on training days and up to 3x30min on off days.

The struggle is getting out of the headspace that loss was what mattered. Since I started taking a scientific approach to my fitness I have been counting every calorie by the gram of food and weighing myself to the tenth of a pound every morning after voiding my bladder. I look better, I feel better, I am definitely stronger, and my cardio ability hasn't been this good since I was at least 22. However, it's been a little disheartening to not see those numbers dropping on the scale, which was admittedly a little addictive, going from losing 8-12 pounds a month down to 2-4 pounds is really taking some adjusting to, even though I know and can visibly see in the mirror that a significant part of that has been a significant increase in muscle and other lean mass.

I don't really think there are any pieces of advice that can help this transition, I intellectually know that what I am doing is better for me, building a healthier body by adding muscle with my resistance training rather than just avoiding loss, and going to better get me to the level of health I desire. It's just hard to switch from that "my goal is a weight" (my original goal was my current weight, just nominal BMI, but as I read more of the science that went down to 180) to "my goal is a body fat percentage regardless of weight" (17% or less, the standard for having a scientifically "fit" physique).

Tl;dr: switching from fat loss steep cut to body recomposition just below maintenance and having trouble getting used to not seeing the scale dropping almost every day.