Writing is not all glamour and perfection. It is hard work, exhausting, soul draining work that takes from us as much as it gives to our readers? So why do we do it? Each of us will answer differently but for me the answer is this: writing is part of my being. Yes, it exhausts and drains me, but then when I am finished it energizes and refills my cup.
I write because I need to breathe.
So, for your bad days, write yourself a note about why you write. It can be a simple phrase, an inside joke, or even an image. Put in your writing space, or on your laptop if you write in many places. Put it where you can find it on your darkest days.
And then, when you feel like giving up–read it.
Read it and remember why you are fighting through the self-doubt, the exhaustion, the never ending work. Remember and then get back to work.