Okay, so maybe you haven't hit your groove yet. Your writing muscles are sore and getting those words out is like pulling teeth.
Hang in there! It'll get better soon.
Writing, like anyother muscle, needs to be exercised. Just like you can't just rock up to your first day at teh gym and expect to run a mile on the treadmill, followed by bench pressing your own body weight and then some refreshing advanced yoga, you won't be putting out 3k of pure brilliance a day if you haven't written much over the last few months.
Which is why I think having daily word counts that stay constant throughout the month are setting you up for frustration and failure. Instead, why not build slowly and gain momentum as you get more writing fit?
For me, I'm going to up my daily word count from 1.5k at the start to 4k by the end with a gradual increase every week. It's a number that works for me because I know I can write 1k a day even when it's all pulling teeth and painful dragging-out of words.
do you know your comfort word count? What's the most you've ever written in a single day? Do you have word goals every day? Week? Or just that shiny end-of-month crown?