How many of today's jobs will be there after TSHTF? Probably less than 10%. Regardless of whether you are a government employee, work construction, move financial data around, sell stuff to any of them, are collecting welfare/SS or whatever. The economy will be unrecognizable when the jig is up.
Earn what you can in ways that are available today. More is better than less if it gets you more prepared. Put what you can into tools, skills, food, supplies, a retreat and defense. If you can find good employment, with good income that also develops skills and tools, that is particularly good. If you enjoy it, that is the best of all.
Know you will never have done enough, but you will be grateful for every little bit you did do. Do not obsess over being in the gulch with your permanent employment settled when none of us can accurately predict what the post-TEOTWAWKI world will look like. But for goodness sakes, get a "vacation home" or get yourself moved into a small community before the doors close.