Fear of failure is a great motivator whilst in the throes of composition. If I ever hear someone say writing is easy, I try to avoid what they have written. (I'll qualify that. Writing is easy. Even little kids manage it. Writing well, now...that's hard, as any craft worthy of the name should be.)
As for targets...I'm not such a big fan. Or at least, hitting your 1000 words for the day shouldn't be a signal to stop (though if you're anything like me, you'll lose track of time as well as word count and just keep on going until, eventually, some internal working brings you to a natural halt).
Now I'm going to 'fess up and admit I don't always get 1000 words in a (6-7 hour) day. Some days I don't get any at all (I spend that time going over other stories instead, in the Quest To Find Them A Home; it's still work, it's still doing the job, so it's all good). But then, on my absolute best-ever 'golden' day, I hammered out slightly over 10,000 words. Ideally, maybe across 2-3 stories, I'll get 5k. More realistically, I aim for 2k. 1k is really a bare minimum - though as I say, I don't always make it and try not to sweat it too much.
While I'm here, here's my hint for those days where your brain refuses to play ball and even revision seems impossible...find a favourite inspirational bit of On Writing, read it, put the book face down beside where you're working, then grab a piece of paper and a pen and freewrite, longhand. Just...waffle away, write anything you like, starting with whatever's handy - the weather, the pain in your big toe, the dog sniffing the rubbish bag out on the pavement (what's in there, I wonder?)...
Works for me.