I can understand your concerns, but I do hope that you are able to find a way to get some reading in. SSM is a really good starting place, and at some point your W should read the first half. The book is softcover and skinny--easy to tuck in your toiletry bag in the bathroom. Passionate Marriage (Schnarch) is the next step, I think, in digging deeper and uncovering specific intimacy issues in your R.
These materials will empower you to articulate with your W in a productive manner. They will give you strength to face her and confront the issues, and conviction. You will not be *guessing* your way through this journey.
As far as "hiding" things from your W... You are simply preparing yourself to unveil the 500 lb gorilla in the room. You won't be hiding for long. Once your start communicating with your W more and more, the books are no big deal. She'll know you're on a mission. I can only think that my library scattered throughout the house conveyed something serious to my husband. This time I meant business and it showed.
Step up the romance today. Ask her out on a date for this weekend. Bring home a sweet treat... Do you have any ideas?
Don't hide from this and don't delay. The longer it festers, the more resentment builds.