Memoir non fiction book

I need help finishing my book. I have a rough draft. It needs more details, feeling's and content. I really need help with that part as that's not my forte. It's currently 15,000 words and I'd like it to be 40,000 words. I need to add more details according to my Editor friend (who doesn't have time to help me write it). My ideal publishing date on Amazon is April 28th, 2021. This book is a self-publishing project. It's memoir style and non-fiction as I'm adding resources to the end. The summary of my book is in my profile and attached with more detail.
Please let me know if you're interested and can work with this timeline.
Thank you,
Jana