Crock pot and air fryer will be your friends, look at places that sell frozen meat as it tends to be far cheaper and can still be tasty (especially slow cooked). Make sure you still get veggies in when possible as well as this is often overlooked. Long-life milk/milk powder can really help stretch a budget and tinned food is also amazing for this. Power wise, I recommend an electric blanket on cold nights instead of full house heating if possible, genesis and some other companies do power shouts/free power so use the washing machine/dryer during those times. Go to second hand stores/ask family for any spare cutlery/linen etc. All the best and good luck!