I imagine law school is not easy too. You have to even pass an exam.
To be honest, the only jobs that care about your degree are jobs in academia, science related or something that you need to pass a bar or exam.
In OP situation, it seems that his eyes are set on operating or managing sports events or gym or something similar. With this, I think you should focus on what you want to manage since I do think management/operation can be learned through experience and not so much with theories and school. So maybe sports science is still beneficial.
If I were in your situation, I would have not turn down the offer in China. It sounds like the job you want to be in.
A lot of fitness industry relies on social media now. So an expertise or know how on that area can help your business. You might enjoy managing sports celebrities or perhaps hone one into.
But again, you need to sit down and think what makes you happy. I can assure you that if you all care about profits and money (unless thats your passion), then you wont be truly happy - you will always want out and do something else.
Congratulations on engagement btw.
Having said that, maybe it is best for you to talk tl your bride to be since she will be with you in the future. You might be even interested in building it together… who knows. I know a number of couples who build their careers together and they doing good. My former boss and his wife have different science labs but complement each other; thus help publications. My coach and his wife do online coaching together.