Two things which I haven’t noticed being mentioned (although I only skimmed so I might have missed):
1) Pathway to Prayer by Rabbi Mayer Birnbaum (the original, in Lashon Hakodesh, is called Avodas Hat’fillah). This is a clear translation/explanation which can either be used before or during davening.
2) Studying carefully the halachos of tefillah. Although they’re different for women tan for men, there are chiyuvim for women as well, besides which, studying the halachos is a tremendous help for any struggle with one’s yetzer hara, regardless of what the particular halachos are.
Hatzlacha!