I went to Los Angeles to become a writer. I'd written three features before I'd arrived, but they were the bushiest of the bush league. A couple years in, I got lucky and got a job in TV and therefore switched gears to working on TV spec scripts. I wrote six or seven of those, each still quite bush league, and I started getting jobs as a writer's assistant. Knowing I could be called upon to offer material in those meetings (you're always being tested for writerly aptitude), I got nervous and scared, and pretty soon, I was getting more and more bound up, to the point where I could see nothing but crap in my writing and couldn't relax enough to be a reliable contributor in the writers' room. It was like trying to get an erection in public -- the harder I tried to relax, the further from relaxation I got. Miserable yet curious about my predicament, I realized that "going to L.A." perhaps had been a coping mechanism for running away from how crappy I felt about myself. My (now ex-) wife wasn't helping when she told me if I couldn't write (or wouldn't, by this point), that our moving to L.A. had been a waste of her life. So I found myself swimming in a vat of santorum composed of doubt, resentment, fear and, most important, self-loathing. I've been doing Zen for a few years, which has forced me to see that my "ambition" may have been merely the foreground distraction of a much deeper, uncertain and unfriendly psychological background. I've had to leave L.A. because of the relentlessly poor job market and took with me two things: the clothes on my back and the aforementioned santorum. A therapist and support groups are probably in order, but your thoughts would be most welcomed.
What you will discover, I believe, after long meditation on your past, is that the drive to write is the drive to discover your true self.
The drive to go to L.A. and become famous is something else. The drive for praise and money is something else. So it is not surprising that when you tried to rope this creative impulse into service it balked. It did not want to sit around a writers' table and be zippy.
So it didn't.
Good for it. Good for you. The you that wants to write doesn't care about the writers' room. This you will slowly come to accept as you practice the art of Zen meditation, I believe. And as you slowly discover and come to accept this fact, your self-hatred will lessen and you will shed layers of protection and people will begin to see who you are underneath. They will like you. They won't turn away from you.
Lots of other things will happen. As you continue to meditate on this you will notice the differences between the voice that is trying to impress at the writers' table and the voice that comes through you like a cold clear river.
This voice of the cold clear river will come infrequently at first since you have been so dismissive, but if you hold still and listen it will visit more often. It might not be the voice you expect or the voice you think you want. But it will be the voice of who you are.
Sometimes we are at war with who we are. Sometimes we have taken sides against ourselves. We have sided with our so-called protectors, for instance; we have sided with family against our true selves. We have hidden our true selves because they get us in trouble, because they invite ridicule, because they are not viewed as cool by the kids we think are cool.
Writing to discover the true self means encountering just how incredibly uncool we are.
Layer after layer of coolness you will shed. You will eventually be the least cool man in the universe. But you will know who you are.
Your writing might not make you money. Maybe you will work at another job to support your writing. That is noble and fine. Most writing jobs do not call you to explore your deepest self. Far from it. They ask for the opposite. So it can be good to not have a writing job, but to write for the purpose of encountering the true self and developing excellence in craft.
There are a few exceptions. Me, at the age of 47 I sort of lucked out with a writing job that actually requires me to keep searching for my authentic self as I write. But this is just weird luck and it comes after hard lessons. I discovered in the 1990s that writing for a living in the wrong way can make the writing voice seize up. So it's not surprising what happened to you in the writers' room. I really believe it was your authentic voice saying, "No way. I'm not whoring myself."
So keep searching and be honest about your deepest yearnings and write from there, and accept your shortcomings and write from there, and let yourself laugh at yourself and write from there, and sleep well and write from there.
Write from your true self. Study the craft. Study its history. Study the medium. Study the language. Keep writing. Enjoy your life.