You cannot push a rope, my friend. And sooner, or later, in life we come up against the hard fact that we cannot change our parent, no matter what their behaviour.
The only thing you can change is your reaction to them. Your problem is not her glaring and yelling, it’s that it ‘works’ on you, upsets you, hits your buttons. Because she knows them all intimately.
You need to get yourself to a place of complete indifference to her demeanor. Imagine her a posturing, pouting, attention whoring, 8yr old in a snit. Would you reward that child with attention, and encourage that behaviour? No, you wouldn’t, no one would. Instead you would feign complete and total indifference. Her looks and glares are only fun for her while they are hitting your buttons. If they don’t appear to connect, she loses her payback. It could take some time, she’s not used to you being armed with indifference.
Here’s a good way to help yourself. Develop a detailed exit strategy. Decide, before going in, at what point the line is crossed. If she glares, stares, yells, that’s your signal, you’re enacting the exit strategy. It should include, how you’ll get away, (bus or taxi fare?), the excuse you’re going to make, (“You’ll have to excuse me, I just got a text from a friend in need!”, or whatever!), and the spine to see it through, once or twice, very likely.
Having such a plan in place, will give you enormous self assurance. Knowing you can pull that trigger, whenever you feel the need, will, surprisingly sometimes, cause you to not need too. The knowledge, that you could just walk out, really does seem to boost both confidence and the required indifference.
Part of you already recognizes, I think, the problem here is really sort of a codependence thing. It takes two to do the dancing. Kudos for recognizing work needs be done on this relationship. Please recognize the only productive work you can do will be on yourself.
I wish you nothing but Good Luck, it’s a very difficult journey you’re on.