It stinks. We all know it, but it's part of the job and so we just have to get used to it. I have, and because of that I can see how awesome some of my rejections really have been.
I got an awesome one awhile back that said something like this:
"You have this amazing energetic voice in your query and your emails, but it didn't translate to the novel as well as I'd hoped.
It's the one thing that can't be taught or coached: voice.
Now you just need to work on the other parts. I'm not sure how you feel about critique groups or writing partners but they can be hugely helpful about some things.
Stephen King said the first million words are practice. That sounds daunting, but it's really not. All you have to do is keep writing. You've got the right stuff to be a writer...it's just not quite ready yet.
There's a 24 hour flaming dog poop delivery service here in New York: 1-800-RJCTHIS! They know where I live..."
Recently, I got another one that looked like this:
"Thank you so much for your patience while I reviewed your work. I appreciated the opportunity to review ORACLE and think you have a lot of talent. The premise was interesting, unique, but I couldn't connect with your protagonist and so I didn't feel part of the story. It was a personal issue and I do not really have any recommendations for change. Since this is such a personal business, it's integral that an agent really be behind a work 100% and that's just not the case here for me and ORACLE. I do wish you the best of luck with your writing and know that you will find an agent who can represent your work with the enthusiasm it deserves."
Anyway, they may be rejections, but these are the kind of things that keep me going and working. Thank you to all the agents who take the time to give positive feedback and encouragement. We appreciate it.