I know it doesn't seem that way now, but I have supported a lot of people whose parents changed, and they didn't believe that was possible, but I think there is often hope :)
Why don't you have a read of this article and let me know what you think? https://www.ditchthelabel.org/my-parents-didnt-react-well-to-me-coming-out/- I know you haven't come out yet, but you might find it helpful.
That sounds really tough; it's so hard when we want more from someone, but it isn't right for them. We can end up feeling really rejected and worthless which can be hard to work through. How are you feeling today? Are you having any contact with her at the moment, or are you having space?