… and more seriously, don't forget that the kid isn't either the end of your previous life, nor the entire meaning of the next. Initially she'll undoubtably be the most important thing, but you still have a job, friends, goals and what have you.
Once you get over the first month or so you will be able to go out on your bike, meet up with mates for a beer or two, etc. etc. Less than previously, and forget disappearing all day without prior warning, but you can still do it. So when you haven't slept properly for ages, you feel like killing the little s**t: there's a light at the end of the tunnel!