hahaha!!  that's actually pretty fucking hilarious!  i'm not going to sit here and preach about how you're a dumbass like some of these other self righteous mother fuckers...i'm sure you're quite aware that it wasn't a great move.  but hey, we all do dumb shit when we're drunk.
lawyer up dude.  i don't know how things work in Canada, but in the US, if you were to lawyer up, i guarantee you that your lawyer could plead this down from assaulting an officer to public intox, or disturbing the peace....something along those lines.  and believe me, you'd much rather have a public intox on your record as opposed to assaulting a police officer.
people are trying to tell you that once you've got a record, you're fucked!  bullshit.  as long as it's not a felony, it's whatever.  it's realistically not going to keep you from getting a job or anything like that.  i've gotten my self in a little bit of trouble here and there, and have still worked for the dod with high level security clearance + a couple of fortune 500 companies...in pretty respectable capacities.  Yeah, I have to disclose it, but I've never had anyone who hasn't laughed it off as being young, dumb, and drunk.  everyone has done something they regret when drunk, so most won't hold it against you.
pay your fine and move on.  shit happens, dude.