"Recently all I ever write is crap. Maybe I'm just not cut out for this."
Sometimes you just need to slog through the muck to find the gold. Keep writing. Wasn't it Ray Bradbury who said he went to work every day and wrote... thousands and thousands of words and sooner or later, something good may emerge from that nice big stinking pile.
To expect everything you write is gold is pure delusion. To work through it regardless is the true testament of a writer.