She's probably resentful of how "easy" your new career seems (I know it's not, but in ways, it is, if it feels natural and fun to you -- most people's jobs are not natural and fun to them, let's just admit that, as adults). And she's probably a lot more unhappy with her day-to-day life or day-to-day work than you realize. That statement was probably one way she's kind of reaching out and showing you her unhappiness, and she hoped you'd be supportive and encouraging somehow (not that there was anything there for you to support) but instead you were (in her view) the opposite with your whole, "Well, what will you do?" mindset. She maybe feels trapped in her job and just wants a way out? I've been there, and I've just quit with no plan (I was younger, I planned to move in with my parents if need-be, not rely on an SO, but I don't see the two as that different) and it worked out for me just fine, with me finding a better, healthier path. Sometimes you just want to leap and you want to know there's someone who cares enough to catch you? I'm not saying you should feel ready to catch her -- that's a personal choice -- or that you're a bad or wrong partner for the way you responded. I think you responded naturally. But I can also see places her mind might be.

I mena, I wouldn't say I hate my job, but if my SO suddenly became a Twitch sensation, loved his job, had "easy" money, and so forth, I'd really feel the frustrations of my job a lot more. My job is really hard. It doesn't pay amazing for how hard it is. (I'm a middle school teacher.) I'm suited to it, but I dream regularly of us having enough money to not work or do what we actually want.

Granted, I think my SO would be like "Hon, come work on Twitch with me if you want!" (but we both like video games) if he was a big sensation and let me do his social media or something and stay home with him. Or, if he could afford it, he'd try to help me find what I wanted to do and support me (financially and otherwise) but we are financially intertwined, getting married, etc. We are not really independent financial entities at this point, but it sounds like y'all are -- I understand those are different relationship stages and there are all different people out there!

I think this requires just a better, more empathetic conversation on both sides. Let her know how you feel but also seek out her actual feelings and focus more on that than the one "I want to quit my job" statement. Where is that coming from? What's going wrong at work? How does she feel about your work and her work?