Utilize Cratejoy to test your concept. Once you are confident you've proven your concept, transistor over to Shopify and the Recharge app to grow your business. Shopify offers a host of apps to help run and grow your business that Cratejoy doesn't.

In addition to the previous answers, the connecting with outspoken advocates for the health condition you're targeting. Leverage their platform for an authentic connection.

A mentor is one approach. You can expect to gain wisdom and insight from someone who has been in your shoes at a point in their past. Based on your question, however, it sounds like you'd benefit more from a consultant or strategist tnat can actually help you refocus on your goals and help you establish a plan to move forward. I'm happy to jump on a call with you to help sort through it all.

Yes; if you do a presale, those buyers will get the book immediately upon release. Include a message in either the front or back matter that encourages them to leave a review once they finish the book. You should also encounter them to join your mailing list, that way you can continue to build a relationship with them.