Don't hinge your self-esteem on the rejection letters that will surely come. Every one is a step forward to the one who will publish your book.
The only way to get rid of the rejection letters is to take your destiny into your own hands and decide to publish the book at your expense. It is a bold move, but many self-published books get picked up later, once its market has been proven.
Don't ask why!
Writers, of course, want to know why their book 'doesn't fit' with the publishing house, especially if they have done their homework and gone to great lengths to find a publishing house where their work 'should fit.'
But editors, when they reject, have been trained not to say the reason. Editors do not want to engage in a discussion about the reason that the book has been rejected, because the author will either argue their point (which doesn't win you points) or offer to 'fix it.' Neither of which the editor is interested in. If the editor thought your book could be 'fixed' to fit their criteria, it wouldn't have been rejected.
If you are not yet well-known and no one knows the title of your book - then your future customers aren't searching for you on the internet.
How do you get them to discover your book? It's easy. The concept is called Associative Marketing and publishers have been using it since time began to sell books. As an author, you also need to tap into the system so that you can significantly increase your book sales on the internet. It is explained in great detail in the book Advanced Book Marketing.
It's not a matter of getting them to notice you and your book, it's putting your book where your customers are already searching for answers, and everyone wins...