One of my favourite writing maxims is, 'To be a writer you need to be an eternal optimist.'
And to succeed, you do need to believe in what you do and keep putting your work and ideas forward. Such is the way of publishing, some work and ideas will get rejected but you must keep going and be optimistic and hopeful.
During the week I was saddened to read one person interested in writing, write 'I have never had anything accepted and probably never will.'
With such an attitude making that breakthrough and getting accepted will be doubly difficult. As Henry Ford wrote, 'If you believe you can do a thing, or if you believe you cannot, you are RIGHT.'
As a writer believe in your skills. And know that if you keep writing, keep putting forward ideas and proposals and retain a healthy sense of optimism (despite the inevitable knocks) you will get results.
Good luck and I wish you and your writing well.