It takes time to come to the stage of indifference. By not being in contact (other than when neccessary due to work obligations) soon enough you will reach that stage. It's like giving up anything that has been a habit, cigarette smoking say. You have to give your body a chance to withdrawl from the nicotine then once that's out of your system one has to work on the psychological (the most difficult part of weaning) aspect until they don't consume our thoughts. We have to train our brain to re-direct the focus off the cigarette and onto something else entirely. Run, walk, jog, go to the gym, ride a bike. Do anything that will get your feel good endorphins pumping.
Hang tuff, you're doing fine. Just practice not dwelling on the melancholy. ;o)
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion