Help with newtonic physics (ish)

[MysticPing2]

So i have this game where you fly a cow in space, and i want it to be newtonic. At the moment when you press "up" you gain speed and "left" and "right" rotates you, the problem is the cow goes into the direction you are rotated towards.

What i want it do do is to add speed into the direction you are facing, not go to the direction you are facing, does it make sense? I have my love attached, i do not want you to do it for me, only to help me with how to do it ( if you do it for me i wont complain though)

[Plu]

I'm at work so I can't give indepth help, but feel free to steal some code from my ludum dare game, which uses the exact same kind of controls:
http://ruigekonijnen.nl/temp/LD27.love