Writing What You Want

I've repeatedly said in posts that "You are the author. The decisions are up to you. It's your book, do whatever you want..."
But sometime you have to sacrifice what you want for what makes sense.

I've developing another rough draft on the side. In it, I want the main character to fall in love with this girl. But that messes up my plot and destroys the personality I've created for my character. As much as I'd love a love story, I can't do it while retaining the character's true form (and the girl doesn't deserve him anyway.)

R.L. LaFevers, when writing Nathaniel Fludd, Beastologist, created a character that she didn't want. On her blog, she said;

While I was writing the first book I ran into the problem of Nate and Aunt Phil having to travel all over the world...and how to make it interesting rather than episodic or a simple tour guide recounting. Drama, I thought! I need to increase the tension! Make Nate proactive!

So I had Aunt Phil send Nate out on the wing to go up to the propeller and see what was gumming up the prop...
And much to everyone's surprise (not the least of which mine) it was a gremlin who was gumming up the works and out she popped into the story.
B-but . . . I didn't want a gremlin in the book! It didn't work! It mucked up the world I was building and mixed mythologies and . . . and . . . No, I wailed!
But try as hard as I might, I simply could not write the book without her. And if you know how life works, it is probably not surprising to learn that for many readers she is one of the most popular parts of the book.

Sometimes, no matter how badly you want something, your book must come first.
Hey, no one ever said writing a novel was easy.