Can I just suggest a resource to help you educate yourself? You’ve got a lot of reading to do, and it is very brave of you to share your process so openly. But you’re in a lot of pain in part because you don’t have an accurate set of facts — just your evangelical background and the generalized tripe you see in the media. The issue of trans youth is not a hypothetical anymore and it has been studied extensively, so maybe some education can direct your process.
I won’t recommend a pediatric endocrinologist necessarily, but I will say a pediatric psychiatrist — ideally one informed by the latest research (not religion) on gender questioning youth — can help you and your child immensely. Deciding not to decide is still a choice that will impact your child, and a child psychiatrist who works with gender questioning youth in concordance with the scientific consensus can help you understand.