I consider writer's block as essentially mental constipation. No amount of straining or forcing is going to get your idea through intact; all it will produce is fragments of an idea that will leave you sore and unhappy. In order to coax the infant of writing out the uterus of the mind, you have to leave it be for a while, letting it ferment within the stew of your mind.
I'll be honest; I've completely lost track of the analogy, but I think what I'm trying to say is that ideas are like energy; they cannot spring from nothingness, they have to be converted from real-world experience. You have to go out and live your life; only then can you begin to think of brainstorming and new ideas. Hell, every day I go out I see things on the street that make me think: hmm, that would make an interesting SCP.
Ideas can't be forced into the world; they have to be grown in the fertile soil of your own real-world experience.
Besides that, it's not uncommon for members on the wiki to go a long time without posting (hell, it's probably the norm rather than the exception), so don't feel obligated to write something just because you're on the wiki.