Too busy?

I was rereading a book of essays (before they had blogs people had to write 'essays') by Umberto Eco called 'How to Travel with Salmon'. One of the pieces he has there is to analyse how much spare time he has in a year. He writes: When the dentist tells me that he has no time available to see me until next week, I believe him, so why do people not believe me when I say that I am too busy to appear at their conference...
He urges all others to do a similar calculation to see how much free time they have.
This is Israel - it is impossible to plan by the year. I am doing well if I know what I am doing a month from now. So I wanted to calculate how much free time I have in a week. Eco starts off with the assumption that he needs 8 hours sleep a night (as well as an hour and a half to get dressed and have breakfast!!!). Since sleep is usually the last thing after everything else is done, I wanted to work out that calculation last.

In a week there are 168 hours. On shabbat I don't do any work (obviously) so subtract 25 hours, gives 143.
i work for torahlab.org 5 hours a day, 5 days a week (25 hours), and have kollel with Rabbi Triebitz 4 hours a day, also 5 days a week (20). This leaves 98 hours. I teach at Midreshet Rachel for 2.5 hours a week (not counting when we run over time) and Shapell's for 3.5, leaving 92 hours.
Davening shacharit each day (on average) is 1 hour, plus another half an hour each day for mincha/ma'ariv, leaves 83. I learn daf yomi every day for at least half an hour = 80.5. I tutor someone twice a week for two hours each time, and have a skype chevruta for 2 hours once a week. I also learn with someone on Thursday nights, and someeone else on Friday mornings for at least an hour each. that leaves 72.5 (plus I am just starting learning with two more people (at the same time) for an hour + each week, but I won't count that, since we aren't starting until tonight).
I am translating a book for someone, which I am supposed to spend 2 hours on each day - 60.5. I probably spend at least an hour each day travelling to and from work etc. = 55.5. I don't always have time to eat, but assuming another hour each day for breakfast, lunch and dinner would leave 49.5 hours.
So I have less than fifty hours in a week to spend time with my wife and kids, to do the shopping, any cleaning/laundry or dishes that don't get done, and for any relaxing/ guitar playing.
That should leave me with at least 5 hours a night to sleep (assuming none of the kids wakes up in the middle of the night and needs dealing with). So will someone please tell me - WHY AM I SO TIRED?