A few years back, a hugely successful book spoke the blunt truth that sometimes the object of your affection just isn't that into you and there's nothing you can do about it. It's a simple, yet profound notion that neither of you has a fatal flaw and the universe hasn't conspired to keep you apart. As the saying goes, it's not personal. Every writer meets that moment when the question must be asked: Is it time to move on?
Before you decide to shelve your manuscript though, ask yourself some tough questions.
Did I query the manuscript too soon? Every manuscript deserves a break before a final edit and polish. That nay be a month, or a week, but if you haven't let your book simmer for awhile, you'll regret it later when you see a dozen ways those first five pages could have packed a better punch. This is easier to fix if you query in small batches. Yes, you've blown the opportunity with those agents that already rejected you, but there are plenty of agents out there.
And speaking of agents, did you research the agents before you queried them? Did you look at their favorite books, their current clients and their stated areas of interest? Was your query concise, professional and did it plainly lay out the protagonist and the stakes in your story? Did you do something gimmicky like writing the query in the character's voice or leading off with a hypothetical question? (If so, please proceed to "Query Help" on QT the forum right now)
Is your manuscript in a genre that's currently saturated? It really stinks if no one will touch your dystopian YA right now, but market trends have ebb and flow and you can't control it. Write something else. There will always be a place in bookstores for vampires and romance and sci-fi and a year from now, maybe you'll get a warmer reception.
Are you a tad bit whiny/needy/bitter on social media? Being a part of a supportive community doesn't necessarily mean you have to share every indignity you've suffered while dealing with rejection. Many agents do check you out on line before making an offer of representation or a request.Make your on line presence an asset.
This is the hardest one: Is your writing just not up to par? Have you tried to objectively compare your writing to other published works in the same genre? Try reading passages out loud, which is a huge help in identifying awkward sentences. Has your manuscript undergone scrutiny by beta readers (not blood relatives) critique partners, or published authors? Have you done a full content edit, looking for clichés, crutch words, tropes and pacing issues? It's never easy to admit that something you've created may not see the light of day in traditional publishing, and yes, great books do get rejected, but sometimes the common denominator is simply that this manuscript isn't the right one.
Every writer gets rejected. Every. Single One. Good queries and bad queries likely get the same form rejection. Before you give up your dream, try as best as you can to objectively assess the reason for your failures. Most of the time, you can fix what is wrong. Writing improves with practice. Queries can be polished. About the only thing you can't control is market trends and the wildly subjective tastes of people in the industry. Press on and never let the fear of failure stop you from pursuing your dream.