Thank you for sharing that site, I'll be checking it out. Speaking of LDS, a book that helped me (if you're into the LDS kind of thing) was https://www.amazon.com/dp/B006G2XO9K which talks about exactly what you said (purity/shame), and has some question worksheets, couples questions, and sometimes pretty frank talk about sex (which is sometimes difficult/awkward to start, but communication IS THE KEY) as well as relationship help in general. Good luck
Have her read this.
https://www.amazon.com/They-Were-Not-Ashamed-Strengthening-ebook/dp/B006G2XO9K
And you should both go to a sex or marital therapist. If she won't go, you should and then you can get professional advice on how to help.