You do know that you lose about 100 hairs a day, don't you? I lose quite a few hairs in the shower too but my hair never looks thin!
I used to wash mine every day since it would always get oily and greasy looking if I didn't. However, the past few weeks I've discovered that it's no longer as oily and I can get by with washing it every other day (which is nice, it means I can sleep in 20 minutes every other day, lol) -- however I don't know if it is always like this, or only because it's still winter and the air is dry (you know how your skin gets drier in winter) -- I hope it will stay like this when summer comes though!