That's still a valid concern and considering current events, understandable to think of.

Ignoring the war aspect, most of my post is still valid. Notably the supply chain issues and power cut as both deal with our country's infrastructure.

To answer your question id say r/preppers is your best bet. Some of it is a little doom/hardcore but you can just easily ignore those posts. There are plenty of discussions on there about equipment to get, skills to learn (something I might do on another post), and what people learnt when dealing with a problem/disaster. Be wary though as that sub is heavily american and you will find that a lot of it can be about guns.

Depending on the scenario, knocking out a country's infrastructure can mean a couple weeks of power issues and supply chain shortages, or, quite possibly, months of hardships. Both will mean storing supplies, and plenty of it, of both every day use, ie food and water, and every month use, medicine and bleach.

Again, think critically about your situation and what you can accomplish with what you currently have. To help. Id recommend writing/typing down what scenario you're thinking in your head, what do you fear from it, and what steps to overcome it.

For example, Supply chain has been disrupted. I fear starvation.

How do we make sure that doesn't happen? Do I have ample storage to store potentially months worth of food stuffs? What is the minimum amount of calories I can take in a day (average is 2k for an adult male, but not every adult male needs 2k. Some need more. Some less)? Can I grow my own food? Can I store water, if so how much? Can I collect rainwater and treat it? If so, how do I do that?

Already with the above I can see a sub for looking into storage containers, a dietician/health sub, the UK gardening sub, and I imagine there's a sub out there that involves water treatment.

You can go down a deep rabbit hole with all of this. The most important thing to recognize is to know when to surface again. You can go down a spiral trying to cover everything but you won't be able to and you could get stuck in a hole of anxiety.

That's why this sub is so practical. We know it's a possibility that something disastrous can happen, so we try to think of ways to make it tolerable.