unless you know for certain that person will be there for you for sure -- I guess only those who have personal relationship can do that for you. Otherwise revealing too much personal information especially those not so exciting ones (like marriage break-down etc.) can always put you in a weak situation -- human being in the office environment are not there to be sympathetic for you, but they can use your weakness against you. But I have some feeling your relationship with your boss is not that bad. Try to mention your confusion with him if you trust him. Otherwise,wait and see how it goes.