When you’ve finished your novel, you’ll probably feel a touch of elation, a sense, even, of artistic achievement. Be assured, this will not last. Now you must submit your work to an agent. They have submission guidelines on their websites these days; and while they’re roughly the same, you should pay attention to the details, the minor differences. Agents like to entertain the notion that you’re submitting only to them (while mostly understanding that this would be absurd).
You’re now engaged in administration, in trying to flog a product. The more quickly you can think of it like this and come to terms with it, the less it will wound you. You do not want to find yourself in a mind-scape where you’re broken and hurt by indifference and practicality. You are one of many outside the golden gate hoping for ingress, one of many voices crying to be heard. And, of course, I know you think yours is special, the one that ought to be heard. The trouble is, I (we/they) think that way too. And for goodness sake don’t bother chafing about all the undeserving voices that get heard and richly rewarded. Bad people win lotteries, and bad books get lucky.
A suitable emotional reaction to rejection should be on a par with your lottery numbers not coming up. Indeed, the rejections themselves are about as dully impersonal as it gets. No-one sane makes plans based on winning the lottery. If you’re simply someone who’s written a (let’s assume good) novel and are sending it out like the rest of us, then you just bought a lottery ticket. You now have more of a chance of winning than those who didn’t. Of course, if your mother-in-law is Editor-in-Chief at a major publishing house, then your chances just improved exponentially. For the rest of us, there’s no use getting cut up about this lack of connection and the advantage it might afford someone less talented. Be honest; you’d use it, too, if you had it, wouldn’t you?