I was wondering on the following. On Shavout night, I stayed up the whole night. As I am unmarried I do not wear a tallis gadol (thus I had someone motzie me for the bracha as I did not make a bracha on my tallis katan after being up the whole night). I then went to bed after davening and took of my tallis katan. When I woke up a few hours later, should I have made a bracha on my tallis katan?
Yes, you should have made a bracha on that tallis katan when you put it back on. This is since you took it off for a significant amount of time, it was therefore considered a hefsek from your original bracha. This would apply even after you get married, and even if you did make a bracha on a tallis gadol, which included your tallis katan. When taking the tallis katan off, it interrupts the continuity of the mitzva and necessitates a new bracha when donning it again. As a side point, when going to sleep during the daytime, it is best to wear your tzitzis because every second you wear them you are fulfilling a mitzva. When we go to sleep at night, we take off our tzitzis because in any case it isn’t the time of the mitzva, but when sleeping during the day it is best to keep them on.