Being a Company of One is a tough job.
Writing IS a job. Not one you need Previous Experience or Qualifications for you. You create the position, write the job description and interview yourself for the job - "Am I good enough? Do I know myself well enough? Can I handle the rejection?". Your answer may not always be objective, but that's what hopes and dreams are built on.
But you need more than dreams. You need persistence. You need to believe in your ability to be a storyteller. You need to understand that you will get better with time. You need to be open to criticism.
You have to realize that not matter how much you steel yourself for it, the rejections are gonna hurt.
There will be days you can't laugh the rejections off, sit down and do ANOTHER edit of a piece, find ANOTHER market for it. There will be days when your morale is low, other parts of life are intruding, and getting yet another rejection is another kick in the teeth.
You will wonder "Why am I doing this? Am I a masochist? Does my writing suck? Will I ever get better?"
Persistence, my friend. Pure, bloody minded, hard slog persistence. When you've Made It, these are the days you'll look back on and remember, and smile and say fondly to Oprah "Why yes, it was a difficult and lonely process, and it takes the right balance of ego to push on through".
This is your Character Building.
You will find out a lot about your personality as a Company of One. You may choose to blindly ignore your writing faults and blame The Almighty Editor "They're the one with the problem, not me! They don't see my sheer brilliance!"
You may operate as a Company of One for a very long time, but there is no harm or shame asking for help or advice. Judge your rejections - form versus feedback. Join a writing group, in real life or online. Find yourself a Reader, if that works for you - for some it doesn't.
It's all standard advice you'll see echoed the publishing industry and blogosphere over. You will feel a little silly for maybe ignoring that advice when you first started out. But it all comes from experience, and yes you have to gain that experience somehow too.
So, hang in there. I know the rejections suck. Balance your ego with your talent, and refine that talent. Find yourself a wee mantra to repeat every day.
"I want this. I can do this. I will get better."
Video: "Affirmation" by Savage Garden, live in Brisbane.