How to Tell Mom About No Longer Being Christian

I know this question has been asked many times. I'm asking it again, though because I want to add my own context anyway.

A few points of context:
- Grew up Christian (Baptist) in an asian household
- Currently in college.
- My parents got divorced during the pandemic. I've been living with my dad since. Due to my mom's situation and frankly mental illness (that she denies), I've found that it's easier to live with my dad though I love my mom and care baout her.
- My dad already knows. Surprisingly, his response was very simple and he didn't freak out or something, which was a relief.
- I'm worried about telling my mom because I'd say she's more traditional and devout as a Christian. Especially bc of her mental situation, I'd say she really relies on her faith to keep her somewhat grounded and perhaps, hopeful?
- I'm not financially reliant on her and I'm not worried about that. I'd also say I still keep a lot of the values Christianity teaches because I think many of them are good.

I'm most scared of telling her because I'm worried it'll affect her mental health terribly. Also, I'm really really uncertain about how she might react. We've had a tough relationship and time communicating because of the divorce and her being very frustrating to talk to. However, I do want to care about her if I can. And I know that telling her I don't believe might feel like I might go to hell. In all honesty, she could react kind of normally or she could react totally like angry- yeah idk. But again, my main concern is how it'll affect her mental health. I could try to pretend for her sake- but I'm worried about how hiding it will affect me in the long run. Like what if I get a significant other who I might want my mom to meet, and she'll ask why he's not Christian or something. Things like that. So idk what to do. This has been stressing me out for a long time.