All of the price comparison sites are currently being totally open with potential customers, telling them that there's almost certainly no point in trying to switch suppliers at the moment. e.g. MoneySuperMarket.com has this on their website:
"What can I do now?
If you're already on a fixed deal then it's likely to be much cheaper than current deals – so stay put.
If you’re on a variable tariff, you can still run a quote with us, but you’ll see a lot less deals than normal. It’s also likely that the deals you see will be more expensive than staying put."
https://www.moneysupermarket.com/news/what-you-need-to-know-about-energy-price-rises/
So staying put, together with thinking of ways of cutting down on energy use (especially on heating), is probably the best you can do for now.