Questions to Consider about Completing Degree

I’m considering going back to school and would like some input or some questions I should ask myself before I make this investment of time and money.
Details: I have been working full-time for almost three decades. I’m closing in on $200k a year, and while more money would be nice, I’m paid well and enjoy great benefits. I’m a well-trained coach and have a small, part-time practice. Through all of this, however, I remain insecure about my lack of degree. I also think that it would be easier for me to replace my high-paying job with another high-paying job if I had my degree. In my coaching practice, my clients are doctors and MBAs. I never say I have my degree and they don’t ask, but I think they assume I have a degree. I wonder if all of this is just another well-constructed obstacle concocted by my mind to keep me small.
Thank you.