Sometimes I think I'm over my mom's homophobia, then other times she'll say something like "gay sex is unnatural" and it just gets stuck in my head. My mind latches onto that one word, and it keep going. I'm unnatural, my sexuality is a mental illness etc. Why does she say these things when she knows I'm a lesbian? She preaches she loves me, and that she doesn't want me to be sad but then she turns around and says this...

If penguins (more famously) and other animals can be gay, then it’s totally natural. I’m sorry your mother is having a hard time getting there and fully accepting you. I can only imagine how hurtful that is for you. I’m sending her acceptance vibes and you lots of comforting ones. ?

Can I ask you a question about your sexuality??

god I feel so sorry for you that sucks :// I can kind of related, I’m bi and my mom says offensive things all the time even though she claims to be okay with the lgbt im sick

Religion is honestly no excuse for homophobia. There are queer theologians who have made many arguments in favor of same gender love and different expressions of sexuality and gender. You might find looking into queer theology helpful. Here is a website made for lgbtq Christians. https://www.queertheology.com/ And an article introducing you to how these theologians think about sexuality and gender. https://preshouse.org/blog/queer-theology-learning-from-lgbtq-christians/