Well, if these are just random, meaningless hook-ups for you, why don't you try putting a hold on it for now until she's dealing better? Focus on her, be her wingman. I mean, if your relationship is barely holding on, why not temporarily stop a behavior that's causing her stress, fair or not?
That said, now that she's had her chance to vent I would call her on her lack of sensitivity. It's not cool to lash out, even when you're feeling bad. Let her know that you're not mad or bitter but that it did hurt and that you'd appreciate it if she didn't attack you in the future. "You feeling bad doesn't mean I did something wrong," as they say.
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.