I think the first thing I would do is unplug everything and then look at your meter. If the wheel is still turning or the number increasing - then you know there's some power going somewhere.
Another thing is to buy a little reader, that goes between the power socket and appliance. The idea is that you connect it to each appliance and record the power usage for a day under normal usage. Even use items like irons, hair dryers etc.
It takes time, but you get an idea of what you are using. Normally something pops up that uses much more power than you think! Some fridge/freezers can be very hungry. Their rating may no longer be correct, because of leakages, seal damage etc. Keeping an old appliance can be false economy.
