Pearl, It's not easy to do - the detachment is so that you can get PAST the uncontrollable crying.
The first two or three days are going to be horrific - I compare it to an addiction - but then it gets easier. Find things to do - especially things that engage your mind. If you find yourself thinking about him/sitch - force yourself to think about something else, or get up and move around.
It is easier said than done, but if you focus, you'll get there!