don't run 5k everyday, it will tire your legs out and you won't be able to run. If you can run 10k then do that instead, with a day break in between to let your legs rest.
As for motivation and diet, the way I think of it is like this, If I eat a chocolate right now, that means I will have to run an extra 2 kilometers to burn off the calories I ate. So the more I eat, the more I have to exercise. What do I hate more exercising or eating. Normally its exercising, which I why i don't eat that many carbs.