I think a third world war is relatively unlikely, as much as news sites and social media are relishing talking about it because it gets lots of attention, we're not actually even at the level of tension of how it was when I was born in the Cold War back in the Thatcher era. I'm from a town where they build nuclear submarines (in fact my Dad helped build HMS Vanguard), and even when I was little "It was like the three minute warning" was a local phrase meaning "it was a chaotic rush" because back in the Cold War, the people of my town all knew that if Russia launched a nuke at the town, there would be just a three minute warning for the people to get to safety.
Russia may have put the retaliatory nukes on high alert to ward off attackers, but hasn't yet put the offensive nukes into the position where they'd be ready to launch within 15 minutes like they were in the Cold War. For the time being, his threats are all just baring of teeth to scare NATO nations from intervening in the conflict. The whole war really doesn't seem to be going according to plan. It seems pretty likely Putin wanted to jump into Ukraine, have it taken over and forced into talks very fast to get the territory he wanted and then shrug at the rest of the world and way "well, I already did it, what can you do?" (pretty much like Crimea), But perhaps he overestimated his army (Or his generals maybe exaggerated the strength of their army, not expecting it to ever actually get tested), or the plucky defence by the Ukranians or the absolute balls of steel their President has. Russia is just bleeding money right now. In a matter of maybe as little as a couple of weeks, Putin won't be able to afford to continue the fight in Ukraine, never mind attack another country like Poland. Like he literally won't be able to afford to buy or make the shells or missiles for the tanks to fire, or to pay his soldiers. It's only a world war if there's fighting on multiple continents, and Russia can barely afford to fight on this one and all its "allies" and even potential allies are just standing back going "uhhhh...."
So mostly try not to worry too much about nuclear war, and instead extend your sympathy and care to those in Ukraine and Russia. A lot of Russian people aren't on board with what Putin is doing and the sanctions are hitting ordinary people the most.
We had an economic crisis back in the Cold War where I was born too. People always talk about the eighties based on how they were in America or in London; big hair, big money etc. But where I'm from, the North of England, all memories I have of my home town being on TV as a kid was redundancies and strikes. Everything was horribly run down back then and nobody had any money. There's an entire genre of British films nicknamed "It's grim up North" about the North of England in the 80s and how awful it was, with titles like Brassed Off, The Full Monty and Billy Elliot to name but a few well-known ones. It was hard. I recommend learning to batch cook food and darn your own clothes, and try to join community groups for cheap socialising.
Look after each other. Be kind. Take breaks and treat yourself to small comforts; a hot shower, a cup of your favourite tea, watching some of your favourite funny show. Get on and make your comics and novels; to many people we're providing much needed escapism.
There may be a week or two of this still to come, but hopefully peace talks will progress. Worrying about it constantly won't change anything.