If you want to be a published writer, this is step one. If you don't believe in yourself, why should anyone else?
I had an experience maybe 25 years ago that has stayed with me. My husband was part of a group from the bank where he worked that was entertaining customers by going to dinner and a play. We were relatively new to the community and I had not met the other bank officers' wives. For some reason, we were one of the last to arrive at the bus. Ken parked the car and we headed to the waiting bus. I was introduced to a couple of the wives and one of them said, "I watched you walk over here and thought what a self-confident person. She knows who she is and where she's going."
To be honest, her comment startled me and I asked how she determined that. "Easy," she answered. "It was the way you walked, the way you are dressed. Everything about you is positive."
Her comments made me conscious of the way others dressed, walked etc. And I found that I could single out those who were self-confident, the ones who believed in themselves.
If you believe in yourself as a writer, you will hold your head high. You will pounce on an idea and start writing. You will not be afraid to submit your work. You will choose markets to submit to that pay better than some. You will push fear aside and be eager to start a major writing project. You will move along your writing journey faster and with fewer bumps than a writer who is filled with self-doubts.
How many times have you read about an avid reader of romance novels who finishes one and says to herself I could write a book like this. Some of them do exactly that. You can bet that these women are the ones who believe in themselves. And some of them may believe but find that writing a novel is darned hard work and never finish.
It's the athlete who believes in himself/herself who forges ahead and sets records. It's the musician who believes in himself/herself who becomes the soloist or first chair in a symphony orchestra. It's the actor who believes in himself who surges ahead of others waiting for parts.
If you have a problem with believing in yourself, there are things you can do to achieve that status. Like the little engine that could, keep telling yourself that you can do it. Remember his famous line? I think I can. I think I can. I think I can. Stand in front of a mirror and say it multiple times. Hold your head high and shoulders back and keep going. Fix your mind on any one success you've had. If you've done it once, you can do it again. It isn't going to change overnight. Time will be a factor. Don't give up. Keep working on building your self-confidence and believing in yourself. You can do it!