I am in the exact same spot. Whenever I do get the chance to go back to gaming/IRC I tend to feel quite bad about it (it's strongly affiliated with being lonely). So what to do now, it doesn't make it easier that the amount of freedom without responsibilities is quite low and tend to show up spontaneously. As it should be when you have kids.

It's painful to let go of those memories and accept that life has probably changed permanently, and with that what kind of activity that fits best.