I'm completely on board with irreplaceable. I think it's definitely one of those options.

While it's a little less than direct, I suggest you write out a short, direct list of things you need her to know, and what you need answered. Likely, How you felt about her before, how you saw that her actions changed recently, how you feel about her now, and what you want or need, which is clarity and some kind of resolution. Tell her that you guys can't move forward in the current state of your relationship, which is hostile, confusing. Try not to accuse or blame, but just tell her that this is how you're seeing things.

Then, write out an email or letter to her and be sure to address those points. Don't write it at a moment when you are angry or bitter, but calm. Try to write it out in 1 shot while you are in the same mental place, put it away for a few days, and come back to edit it when you're mind and eyes are fresh.

If you can't speak to her and get the answers you want, writing a letter will at least allow you to say everything you need to say with interruption, her walking away, whatever, and you know you've done what you could to salvage the relationship. At that point, it will be in her hands to decide what your fate as friends is. Hopefully, she'll put her passive behavior aside and will tell you what her problem is.

And if she doesn't, at least you'll have tried, won't have any regrets about how you handled things, and can put some end to this madness.

Good luck xo!