Good work on cutting out junk media for four weeks. You report that "it is a noticeable change, but have yet to dramatically alter [your] productivity". It sounds like you weren't wasting much time on YouTube, Reddit, Facebook etcetera in the first place, which is a good thing.
We seem to be on the same page that your next step should be physical.
Otherwise, your plan is completely wrong. If our primary objective was to increase your physical fitness then your plan would be a good one. We want to increase your agency. Agency is built on a foundation of self-reliance. Hiring a physical trainer is the opposite of self-reliance. Spending money is the opposite of self reliance.
You are a wealthy person. Having lots of money is great. But when you have lots of money it is easy to become reliant on people and things. (Relying on your friends and family is fine. Relying on personal attention from hired specialists decreases your agency.) The primary purpose of a personal trainer is to get you into the gym. In other words, a personal trainer's primary purpose is to provide agency for a client. Abnegating your personal motivation to a hireling outsources your self-motivation. I recommend you decrease your reliance on commercial products and services. They make you weak.
We live in a civilization. It is impractical not to rely on other people at all. Where to draw the line? I recommend buying commoditized products most of the time—stuff like rice and Subway sandwiches. Rich people spend too much time with trainers, therapists and coaches. Don't use individualized services except on special occasions. (Farmers' markets are permitted on the grounds that they are harder to use than the commoditized alternative.)
The most intimate way to break out of the habit of getting served by others is to cook your own food. If you were single I would recommend eating rice, beans and cabbage for two weeks. You have a family. It would not be fair to subjugate them to such a regimen. Instead, your assignment starting Wednesday, July 21st is to cook dinner for your family every night for two weeks. No TV dinners or ingredient-and-recipe meal kits. Pre-made sauces like the ones used for 麻婆豆腐 are allowed, as are boxed mixes. You will buy the groceries and do the dishes too. If your wife usually does these tasks she gets the time off. If you don't know how to cook then I can provide you with easy Chinese recipes your family will probably love.