I'm new to offering my thoughts and support so what I say may not works for you. I'm sorry you feel this way. I've felt the same way for the last couple of days: shock, dread, despair, only alleviating after some musing.
Firstly, I'm no military analyst or geopolitical expert, I was more leaning with the belief that Putin was bluffing with Ukraine but, well, here we are. Despite this, I certainly believe Putin attacking NATO is absurd, along with NATO intervening, based on the fact that wars are expensive, destructive and in the case of a nuclear war, unwinnable. Even in a nuclear war, I doubt Australia is a primary target, save for a few key bases like Pine Gap. Right now the fog of war and all the confusion that comes with it is draped over Ukraine, and could be for a long time to come, "wars do not end when you please" . So what ultimately happens remains yet to be seen, we could be surprised for all we know.
Second, what yggdrasil and James1 have said is pretty much on point so I won't parrot what they've said, only to say: beware the scare tactics of sensationalist media. Understand they want eyes glued to TV screens and articles, emotion helps generate that viewership.
With these out of the way, here is something I learnt from Seneca, and this helped my with my anxiety in general: "I now warn you not to drown your soul in these anxieties of yours; if you do, the soul will be dulled and will have too little vigour left when the time comes for it to rise."
"Accordingly, some things torment us more than they ought; some torment us before they ought; and some things ought not to torment us at all. We are in the habit of exaggerating, or imagining, or anticipating in sorrow."
On a more relevant note I would say: To carry the weight of the world on your shoulders is to afflict yourself with all the pain that it brings. History rhymes, and is constantly in the making, the only thing we can do is accept it, bitter as that may sound. Regarding your thoughts on your future and career paths, I'd say just go for it, make it is your purpose at this moment, our lives are all that we know until the next one comes. We all become dust in the wind with time, but what was it that raised you from dust to begin with?
I know stoicism isn't for everyone, but I've been in your place multiple times, and I'm just sharing what worked for me. :)