Hi. I'm someone who created and led a secular nonprofit organization for a decade. I'm also part of PFLAG.
As a secular leader, I have seen too many cases of families disowning and kicking out their children for the temerity of "coming out" - of either the atheist or gay closet.
If your parents are as fanatic as you seem to suggest, and if you depend on your parents for food, clothing and shelter, then I HIGHLY suggest that you do not open up to them. Not until you are completely independent.
I am an atheist, but I spent 20 years as a believing Christian before getting to this point. I still enjoy reading the Bible, because it makes so much more sense when you read it as mythology. (It makes as much sense as Zeus turning himself into a swan in order to have sex with a mortal!)
One way to get through church services is to treat the whole thing as an exercise in anthropology. Cast yourself as the person who has snuck into the midst of a foreign culture, and study their ways. What is the social ranking order? What sort of social signalling does each member of the congregation do?
Be like naturalist Dian Fossey, and study the "Christians in the Mist".
Work on becoming independent. Figure out what that means for you, and work to make a path to get there.
One last bit of advice. From my observations, controlling Christian parents will snoop if they believe their child is "slipping" (whatever that means to them.) Don't write anything down about this unless you have it locked down tight behind passwords and encryption. Clear your browser history, don't leave yourself logged in anywhere, and never let your browser remember passwords for you. Locking your PC won't be enough.
I would suggest using a browser from Portable Apps placed on a USB key, in a Veracrypt folder. Use the "Plausible Deniability" feature of the encryption in case you are forced to give up the password.