What I've learnt about the traditional publishing industry is to be okay with rejection.

I write what I love which a lot of publishers tell me is not what's currently selling in the market. They have to take into account their costs, strategy etc. Now, I know I will never write to please a market so I have to be okay with this rejection and find my own way and wait until a time comes where some publisher believes in my work enough to publish it. Or another publisher comes along and finds it worth publishing.