Is my product too vague?

I’ve written and self-published a book and e-course all about achieving dreams through creating a healthier mindset. My book covers finding direction, goal setting, and goal achieving, but it isn’t specific to any type of goal. My target market is adventurous and outdoorsy people who are looking to push themselves more in the sports and activities they do however I don’t make it sport-specific (so it may apply to skiers, hikers, mountain bikers, etc.)

I’ve been selling it through my youtube channel and IG for the past few months but it’s not doing as well as I’d like. I’ve had amazing feedback from the people who have taken the course, however, most people that I’ve asked to buy just don’t get it. They seem confused and usually just give me a neutral or no response at all. My problem seems to be that I’m not asking in a way that makes sense because I know that every single subscriber that I have wants to improve at their sports/activities.

So my question: Is my book and course too vague? Perhaps it would be better to have a goals course for each type of sport I specialize in. The problem is that it’s a physical book and video series, and changing it means scrapping an incredible amount of time and energy, re-writing and re-filming. I really want to find a way to sell my course the way it is because I know it’s amazing and effective. I just haven’t found a way to make it resonate with people. Any advice?