I see - so there is not much you can drop. Sleep is very important. Many issues, including problems with executive functioning, concentration and what not, resolve by themselves once the sleep schedule is in order. Your future doctor would want to know how you function and how your moods are when you meet the sleep requirements for your age (what are they - have you found out?). Just as an experiment, try meeting the sleep requirements for a month while moodtracking (all mood tracking applications include a field for hours of sleep since it is a crucial factor in bp management). You might discover that though you have less free time, your quality of life is immensely better when you sleep enough. That would be a worthwhile tradeoff, in my mind.