I'm 58 and I've lost over 30 lbs (180 - 149) in the last 5 months. I've used basically the same technique you describe. I've tracked every calorie and learned how to prepare mostly plant-based (raw, whole food) meals. However, I exercised more than you describe. I like to walk so I've been walking 25-40 miles/week. When I walk I can eat more and stay within my calorie deficit goal It became a virtuous motivational feedback loop for me. The other benefit of the exercise is that I haven't seen any indication of muscle or strength loss while losing the fat.