It's not really about feeling 'unsettled' (or concerned, or wake-up-screaming-in-the-night-terrified, for that matter). It's about what you are going to do about it.
My income is down, my time in work is down, so I'm using some of the extra time to explore new areas of business. Slow progress, I've put in a lot of effort for little tangible reward, but I've got an interview tomorrow morning - off the back of my 'hobby' efforts - that might lead to paid freelance work helping to develop an app. Could you do something similar, look to pivot to a related field that is less affected by the current situation?
If it's specifically an issue that you no longer feel your employer is giving you what you deserve, can you leave that employer and work somewhere else? Even if you are paid less in a new role, you might find that the job is less pressured and you lose the sense that you are undervalued because your salary is more in line with the effort you are putting in?
If, as you suggest, you can get by on a fraction of your current salary, could you do that for real? Simply walk away, retire, and devote the rest of your life to whatever it is that gets your pulse racing? Who knows, you might find you can generate some income out of that, depending on where your passions lie. It won't be six figures, but it might cover your costs and make you a happier person.
You have options, if you are genuinely unhappy with your situation. If these options aren't likely to work for you, unfortunately you probably have to suck it up. And that, broadly, is true regardless of income / wealth.