I think right now a level of anxiety is normal, but please do not let it consume you.
The reason NATO are being so adamant about not entering Ukraine, is because they know they can not endanger hundreds of millions of civilians. They just can't.
Also if you are here on the British isles, and a NATO conflict begins, we have somewhat of an advantage of being an island. Nobody can amass 100,000 troops on our borders and storm in. We would see them coming from miles off by land and by air. We have an exceptional Navy hence why it's the most funded branch of the armed forces, it can defend us, along with the Royal Air Force and the Army.
Do not fret over nuclear war, it's not going to happen, it just won't. I think someone will put a bullet in Putin's skull before he gets close to that "red button". His government and economy is being destablised by the West, the grumblings are there, oligarchs speaking out, other public officials. For every one that speaks you can bet there's ten agreeing in silence.
It will be ok for us here. All we can do sadly right now is sit and watch, the people of the Ukraine need our support, they know we can't come but knowing the world is on your side is one hell of a morale boost.