Oh I'm so going to regret wading in here
The problems are multiple and there is no 'right' answer, only least worst options. That's hard to deal with but whatever is done things will get worse before they can get better. We live in a globalised society, we are all mutually dependent whether it is energy, services or physical trade. Brexit was sold on a principle, but whatever way you voted there is no doubt now that it has damaged trade and increased the UK's need to have better self reliance for goods energy and services.
We need energy, it's what our modern society is built on, but we've effectively been building up a sustainability debt by reliance on fossil fuels and imports. We have only two options, increase energy production or reduce consumption, and realistically this is a both not an either or scenario. UK homes are poorly insulated and energy inefficient which previous governments have tried half heartedly to address. A wide reaching strategy is needed to improve building standards, relax planning rules on fitting double, triple and vacuum glazing on older buildings, and minimise taxation at both the business and consumer ends of energy efficiency products. Similar strategic changes to energy production, including relaxing regulation on on-shore wind generation (sorry but those people who object to their appearance are going to need to get over it), tidal and solar farms. Nuclear will also need to increase but the lead in time for these is soooo long that it will not address the cost anytime soon.
I don't support nationalisation of service, it is a recipe for inefficiency and lack of investment based on our own history of nationalised services, and of similar across the world. I do support government having significant shares in the companies which gives them a seat on their boards and a return on investment, I know that's legally complex but it could be made to work.
None of this helps this winter - well rapid approval of some generation projects already in process would help a little, but only a teeny bit. French like price regulation is probably the only short term option, but maybe not at the level they are at to avoid the companies selling energy at a loss. None of this is rocket science, but much of it is politically poorly palatable since complex messages that start with 'this is going to hurt' don't tend to win elections.