NFP is no longer equivalent to “the Rhythm Method”, which was notoriously unreliable. Nowadays, NFP (also known as Fertility Awareness Method) is extremely effective…as effective, if not more, than artifical bc means. The only thing is…you have to work at it. You have to be willing to pay attention to your cycle, to invest in taking your temp daily and charting (you don’t have to do that, but it’s helpful!), be willing to abstain from relations for possibly large chunks of time during your cycle. We practice NFP right now and since I am no longer temping and charting, I’m just using my cycle and checking my Cervical Mucous, I try to err on the conservative side of sex…there’s about a 10-14 day span where we abstain. So far, it’s been 21m and no pregnancy.
I know it’s not perfect and I know the concerns you have. But surgically sterilizing yourself is so permanent. They say they can reverse it, but that is not a guarantee. Just really think long and hard before you do this. YEs, your health is important of course! God doesn’t want you to hurt yourself. But he also doesn’t want you to go against His plans. You have to have faith that He will take care of you.
Many prayers for you while you weight this important decision!