As they say, expect the worst but hope for the best.
You know your family much better than anyone here, so I think you will find a way that works for you. Very often, the highly religious families are conservative and do not have open minds. I have two brothers like that. The problem is that they are not willing to listen to anyone who is not behind a pulpit. When they start telling me that I will be going to Hades, I just nod and assure them that my Savior Jesus Christ disagrees. Then have them read Galatians 3:26-29.
In some cases, it may not be a religious-view type of attack, but one of ignorance. They do not know anyone who is transgender and may not know anything about the subject. If they will listen, you can explain that they don't need to know all about it. You are still learning about it yourself. But you are still the same person. The only difference is that now they know some intimate details about you that you have never shared with anyone. As a sign of trust and honesty, you decided to share this information with them.
It still might not go well, so be prepared. But it is very important to let them know that it is okay for them to feel shocked. It is okay for them to ask questions. If you don't know the answer, say that. You can always find out and get back to them. The most important thing is to give them time to process this new information. It won't be easy for them, but if they love you "unconditionally," they will at least try to understand. My parents gave up trying to understand. But they agreed to accept that this is how I choose to live my life, whether they agree with it or not.
Take any little win and give them plenty of time and space to come around.