AITA for expecting my girlfriend to pay proportional rent and bills?

I (M29) have lived together with my girlfriend (F29) for three years. We have always split bills and rent proportional to income (she introduced this idea and explained why she supports its equitable breakdown) and we both do chores and housework equally. Up until a month ago, I earned almost double her income. However, my company has been doing pay cuts and my girlfriend recently got a major promotion, so now she makes about 50% more than I do.

However, now she wants us to “either keep the rent/bills pay distribution as it was before” (as in she pays 35% and I pay 65%) or she “will pay 50/50, max.” I asked her why we are not doing proportional splits anymore and she said I should just be grateful that she is flexible enough to upend her finances for me and split it 50/50. She’s been cold with me recently and told me she shouldn’t have to punish herself for her financial successes and that my “lack of adaptability is off putting.”

AITA?