Buy an electric blanket. There are many offers at moment. Use this in your sitting room when watching TV and take to bed with you if you wish to. Eat warm/hot food and drink hot tea or hot chocolate drink to keep your insides warm. Keep your central heating on when you need it and switch off when you go to bed. In bed, get a 15 tog quilt to cover you up. Find old towels or bedsheets and place on the floor behind each of your doors. Shut doors. This will stop draught coming in. Tape windows up to stop draught coming in. Wear warm clothes and socks, wear warm slippers to walk about in the house. If you can afford to, buy a dehumidifier that has capability to dry your laundry as well as your walls. This will keep condensation out and warm the rooms a bit more.