What makes a writer?

I have been working on a novel for, dare I say it - embarrassingly enough - years!  I start writing and get excited about the work that I am doing then the inevitable pops into my head - rejection.  What if I spend years devoting myself to writing this novel and nothing ever comes of it? Will that be good enough for me?  I'm sure my friends and family will read it just to make me feel better, but is that enough?  What makes a person a writer anyways?  Is it the fact that they write, or is it that they took years of schooling to learn the proper grammar and the proper way to write?  Could I be justifiably considered a writer just by grabbing a piece of paper and a pencil and writing down what I believe is good?  

I want nothing more than to finish this novel.  It is one of my goals in life to at least complete one novel whether it gets published or not.

I stopped writing for a few years because the main character in my story was pregnant.  I had been trying for 6 years to get pregnant myself.  I could just no longer bring myself to write about someone being pregnant when that was what I wanted the most.  I told myself until I experienced being pregnant for myself I could not emotionally, write about it.  I now have an 8 month old daughter and no more excuses!  However in my mind it keeps taking me back to rejection.  I know that my writing isn't perfect and never will be, I didn't go to school to write, I don't know all the proper things about it.  The one thing that I do know is how much I love to write.

So...hopefully sometime in the near future I will be able to officially say I wrote a novel!