You're paying for sky...and complaining you can't afford to heat your house - do you need to re-evaluate your priorities and think hard about what you are spending your money on?
You came for advice. Unequivocally - something does not stack up - something is wrong - you are overlooking something. Do you want to reduce your bills or not? You're going to have to accept that you are going to have to look harder to get to the bottom of this - and maybe explain a bit more about your house.
It seems like you don't have a clue about where to start looking - you've mentioned lights and laptops and miscellaneous things that generally use very little energy. OK - one question - is your laptop several years old? Does it basically run flat pretty quickly when you disconnect it from the mains? It could be that your laptop battery is so dead that it's continually charging - you might be better off taking the battery out and just running it off the mains...anyway.
Are you sure your underfloor heating "system" is off - just because you can't feel it producing any heat - isn't there an electric pump in the system that circulates the water - is that actually running? Do you know where it is - can you hear it running?
If you've looked at any of the other threads - it's been mentioned by me and a couple of others - an old fridge/freezer could be using a lot more electricity than you think - can you hear it rumbling into life on a regular basis? At night? The pump (compressor) circulates the coolant IF the thermocouple (which might also need to be checked) tells it to operate because the F/F is not cold enough - the compressor turns the coolant gas back into liquid and the liquid is circulated - the liquid uses heat (takes heat) from the contents of the fridge and evaporates - this is fine normally but a big problem, a common problem in many old appliances because the coolant has leaked out of the system - the F/F keep operating to circulate a small amount of coolant around the F/F to try and keep the contents cool. My 25 yo F/F was using 25-30% of all my electricity - I used a power measuring plug to check how much it was using - I replaced it and it paid for itself in 18 months.
Things like washing machines. dishwashers, tumble driers, electric showers, electric ovens - these are what you should be looking at. Check the basics:-
Washing machine - we use it on 30C programs (or 40C if we really need to) - typical wash time is 42mins. Once a week - only 2 adults - both of us recently retired so home most days.
Dishwasher - lowest temp - ours is 35C. Twice a week.
Fridge - ours on the highest temp possible 5C
Freezer - ours is on the highest temp possible -18C
I use my oven as little as possible - once a week is accurate. If I do put it on - I shove a load of potatoes in too and leave them to cook in the heat left in the oven after I've turned it off.
People overlook the fact that your gas boiler also uses electricity - when was the last time you had that serviced? The more often your boiler kicks into life, the more electricity it will use - it's not a huge amount but enough for me to notice in my daily electricity readings that it's been a cold day.
You and I can live in the same design of house with the same boiler and the thermostats set to the same temp (say 18C) yet mine might use far less gas to heat that your simply because my house is better insulated - your boiler might be turning on and burning gas to keep pushing your thermostat back up to 18C several times more often than mine so of course your will be using a lot more gas than me; insulation does matter - it's not just about the temperature you set the thermostat to. Have you thought about your insulation? I currently have foil bubble wrap (the sort you normally put behind radiators) Velcro'd to a number of windows and doors - it's ugly but I'd rather not give the money to energy companies and spent it on something else so I'm making an effort to save what I can.
I'm with Shell and their rates are:-
Unit rate per kWh: Elec - 36.448p
Unit rate per kWh: Gas - 10.344p
Standing charge: Elec - 48.59p per day
Standing charge: Gas - 28.48p per day
Dec Elec usage - £78.84 (excluding standing daily charge) / 31 days = £2.54/day
Dec Gas usage - £166.28 (excluding standing daily charge) / 31 days = £5.36/day
Total = £245.12
Dec - Elec standing charge = 31 x £0.4859 = £15.06
Dec - Gas standing charge = 31 x £0.2848 = £8.83
Total = £23.89
Total for Dec = £269.01
My situation is very similar to @7yearsbadluck who said:-
I WFH and live in a 4 bed 1960's semi and have the heating on 18 degrees for 3-4 hours a day (doesn't get below 16 degrees in the daytime)... exactly the same for me: 1960's semi - it's never higher than 18C - mine is on most of the day - but if I can stand it at 17C or 16C - because I'm wearing warm clothes (Marino wool bae layers!), busy in the house or been in the garden or walking the dog etc - then I turn it down. It's put down to 15C at night - not that it come son unless it's exceptionally cold overnight - it was -5C a couple of nights back - I heard the boiler kick in then some time in the middle of the night.
Look - it's horrible to be cold and worried about the bills but you've got to find out where all the electric and gas (and heat) is going because - your bills/usage seem higher than you can account for - unless there is a problem with your meter (unlikely IMHO - I used to work as an electronics and software engineer for companies that made electricity meters!) or with your billing information/meter readings. Is a previous debt being recovered on your bill for instance?
Can you get an electrician to come in and look at your usage and try to pinpoint where the electricty is being used?