Keep writing. It's a really lame answer, but it's completely true. "Writer's block" is really "writer's trip." What I mean by that is it's just a little stumble, usually caused by self-confidence or even just a bad day of writing. Get your feet and keep walking.
You think what your writing sucks, so you think you suck, so you sit quietly and contemplate your suckitude instead of just working. Every 1st draft sucks - you're part of a long, proud tradition. Hold on to that comfort and keep writing. You can fix it later.