As I have mentioned before, Jeffery Lewis (a well respected analyst in the field of nuclear weapons) keeps a close eye on Putin's personal life. Putin is not about to kill himself and everyone else. He enjoys his huge palaces, his collections, his hobbies and so forth. He likes luxury, he likes being alive. Most analysts are certain Nikolai Patrushev will be the next president. Patrushev is one of the few people still in Putin's inner circle and would most certainly allow Putin to avoid any legal or other action against him. Nobody would win a world war. Few would survive and those that did would end up in the stone age.
I suspect that even within Putin's inner circle their isn't anyone willing to die, to see everyone they know die and see Russia destroyed utterly.
It isn't like Russia is facing an existential threat. Nobody is planning to invade, nobody is planning on attacking them. In those circumstances, then nuclear weapons would be used in great numbers, but as it is, it's just a misjudged invasion that has shown how corrupt & incompetent the Russian military is. It's an embarrassment.
Last week it was announced that 1.5 million winter uniforms had 'disappeared' and so as I understand it, they will struggle as winter sets in. But if they leave, I don't think any Russian soldiers will face charges of war crimes much less Ukraine getting any reparations. So while it's terrible politically, it isn't going to end in a world war.
Lastly, China is going to be the nation Russia will fear the most. Russia has a very weak high-tech sector and cannot produce processors of any size. If Russia used 1 tactical nuclear weapon, it would give China a good reason to Sanction them. That would see their industry totally decimated and since only China would know when sanctions would end, only Chinese investors would buy... and they would buy it ALL. Without a shot being fired, China can destroy Russia financially.
But if you are so sure, I recommend you sell all of your possessions, max out all of your credit cards and enjoy whatever time you think you have left. For myself, I'm just going to presume that the war cannot last through this winter and hope that it ends sooner rather than later since people are dying purely for vanity.