2 years wasted trying to decide on a niche

Hi! I’m currently researching my niche. Honestly, I have so many ideas that I just keep going in circles! Seriously. I’ve spent at least 2 years starting and stopping because I can’t seem to settle on a niche and go for it. Are there any resources you recommend for researching the demand for a particular niche? Any other advice to help me just pick one already? I’m an oncologist but am working on my board certification as a Lifestyle Medicine physician. There are so many niches within which I am truly an expert. It’s a good problem to have, but I just can’t seem to pick one. I’ll start with one then convince myself that no one will be interested. So I’ll stop, get distracted by life, then start searching again a few months later. Help me stop the madness!