I think honestly your odds of success are really low unless you're super good looking and present very well on camera. Honestly, that's probably even not enough these days with the infiltration of AI into the space not to mention the GLP 1 revolution taking place at the same time.
I have 25 years in health/wellness/fitness. I've owned gyms, done more CE on corrective exercise than I care to admit, have a gym worth of equipment, have opened in 3 different places. My undergrad degree is exercise science and my professional degree is in a similar space. I make my $ on the healthcare side of the fence rather than fitness/coaching but have experience with both. I know dozens of people who've tried to do what you've done in one form or another and it's a very, very difficult road with extremely low odds of success.
The money in health/fitness is in selling guys like you the certifications, equipment, services on the implied promise that you can start your own business and live out your dreams of being a coach and changing people's lives...
"Working hard" sounds great but also consider that if you spend 1000 hours a year trying to get this business off the ground, and it will take that and more, that's 1000 hours you won't have to spend with your wife and child, or hunting, or doing any other thing you value. You can't get those hours back.
It's best to see the reality of these things rather than the "rose colored glasses" version that the institutes, coaches, and salespeople will present, all so that they can get their $ before you know the hard part