I never feel like I accomplish enough in my day and that I always spend it doing unproductive things like reading or writing for fun despite having 20,000 words in final essays due in the next two weeks. Even during normal life, I feel like I'm just wasting my life away and should be doing something else - it gets a lot worse during stressful periods in my life. 

I am really, really lucky that I naturally don't need a lot of sleep to function (my entire family averages \~5.5-6 hours a night). The only time that I've had academic problems because of insomnia/bad sleep/etc. was when I was got less than 15 hours of sleep in five days (4, 3, 2, 1, 1). I'm averaging about 4-5 a night and even then, I feel like I'm sleeping too much. It doesn't help that I feel much more energized when I get less sleep, though I'm assuming that has to do with cortisol and adrenaline rushes. 

I know it's a terrible mindset and horrible for my health, but I don't know how to fix this.