I highly recommend checking out this blog dedicated to NFP:
live-love-nfp.tumblr.com/
The person who runs the blog is Catholic and she’s training to become an NFP instructor. She’s quite known among the Catholic tumblr community for being really knowledgeable in NFP, Catholic sexuality, reproductive health, etc. and will answer almost any question that gets asked and even if she doesn’t know (since she’s still in training), she will probably point you to the right resources that do.
Here’s a quick infographic along with a few links to great resources she posted at the bottom that explains FAM, but also applies to NFP:
live-love-nfp.tumblr.com/post/125441437773/nfpfam-resources-the-different-methods
Also, here’s her resources tag where she posts some helpful resources like books for NFP learners:
live-love-nfp.tumblr.com/tagged/resources
If you go to her blog, she has a link underneath her description that says, “Got a Question? I might have an answer!” You can click that and you can ask her any question anonymously. If you ask a question anonymously, just be sure to check back on her blog everyday to see her answer to your questions. Maybe you could tell her what you posted here.
And as the person above said, find a certified instructor! Even the woman who runs the NFP blog will probably also encourage you to find an instructor. And yes, there are NFP organizations out there that have instructors who can teach you through the internet, like through online courses, video chatting, etc.
I admire you so much for considering NFP! Don’t let your fear stop you from learning NFP. The fact that it will help you to understand your body more, allow you and your husband to work together, and respect God’s design for marriage is worth it enough to learn and practice. I will be praying for you and your family, God bless!