The British Empire was rapidly weakening. It didn't have the resources to maintain it's massive navy, and the head-start it had in the Industrial Revolution had waned. Germany was an ascendent power and the UK was no match for it. The UK was very much fighting for survival - the counterbalancing alliances of European powers had been in considerable tension since at least Germany unified.
Look what it took to bring Germany and its allies down down - the immense manpower and resources of the Soviets, the industrial might of the US, and the naval power and combined might of the UK and the Commonwealth. And good old General Winter working for the Soviets. And this was only 20 years after WWI's peace treaty where the factories of Germany were stripped of heavy machinery. The UK was certainly fighting for survival. When you get bankers training to use catapults seriously intending to use them (however comical the Home Guard was at times), you really are in the grip of total war, fighting for your survival.
Britain made more planes than Germany except in 1944, made more tanks, except in 43 and 44 (when imports radically increased. It's navy was growing throughout the war. It out produced Germany in many important measures. The army grew and the workforce grew. Yes, it was hard, but total war was what the Russians and Germany fought, not the British. Casualty figures tell us that.
Total war refers to how a society mobilies resources for war, not the casualties it sustains. The UK shipped children out of London, introduced rationing, blackouts, sustained and conducted bombing runs against civilian centres to strike at production, engaged in conscription, sustained and conducted sinking of merchant vessels, and used its political power to pull in every ally it could find. Just because an army didn't land on Great Britain and lay waste to the land doesn't mean it wasn't total war.
How would you describe the difference between the war experiences of those from USSR and Germany compared to Britain? There is a fairly striking difference. Part of this is due to a totalitarian regime, but more is due to the catastrophic effects of the war. Rich countries had a considerably easier war than poor countries. Britain was a rich country. While it didn't finish paying for its World War Two loans until 2006, it is a sign of an incredible wealth that it got the loans in the first place. http://news.bbc.co.uk/2/hi/6215847.stm
Edit: And to more directly address a couple of those points, many countries had starvation, with vast numbers of deaths in both civilian and military populations. Britain didn't as far as I know. Children fought in many battles and the elderly and infirm too (as much as possible). These things also didn't occur in Britain, with the exception of children who lied to get into the armed forces, which at times may have been officials turning a blind eye. Perhaps it was total war in Britain, but it was certainly an easier and cheaper war than others experienced. A low grade total war?
Look what it took to bring Germany and its allies down down - the immense manpower and resources of the Soviets, the industrial might of the US, and the naval power and combined might of the UK and the Commonwealth. And good old General Winter working for the Soviets. And this was only 20 years after WWI's peace treaty where the factories of Germany were stripped of heavy machinery. The UK was certainly fighting for survival. When you get bankers training to use catapults seriously intending to use them (however comical the Home Guard was at times), you really are in the grip of total war, fighting for your survival.