When you're new to writing, it can be hard to know when the right time is to send off your book for...
Separating constructive criticism from your own self-worth
When an author sends their work to a developmental editor, it's because they are aware that work needs to be done to improve the story. Whether that is in the pacing, the emotional depth, finding plot holes, or simply making sure the story makes sense, the book is sent to editing to ensure the story is the best it can be before publication.
One thing some authors, especially new or very nervous authors, struggle with is the difference between constructive criticism of their story and criticism of them as a writer, or even as a person at times.

Most editors understand that, when a book comes in for editing, the author has done the best they possibly can to write and polish a well-rounded story. And we also appreciate and fully understand that, for authors, their book is an extension of their heart and soul.
That doesn't, however, mean that improvements can't be made, and it's also possible that a few plot holes might still have slipped through the net. Trust me when I say even the most phenomenal authors STILL receive heavy critiques of their work. That's the same whether they've been publishing for a month or forty years.
It is SUPER important for authors at every point of their career to remember that constructive criticism of a piece of their work is NOT an indication of an editor's (or an alpha reader, or a beta reader's) feelings about you as a person or as a writer.
Every writer needs to hear outside opinions in order to grow and learn; otherwise, writing stagnates, and with the speed of the industry and the ever-changing tastes of readers and the evolution of language, it's a must to make sure you're moving with the times and always willing to take advice on board.
You don't have to accept every piece of advice you're given, but it's imperative to keep in mind that, if your manuscript is returned with a bunch of changes requested or things to consider, it's for the sake of the STORY. Your editor is not trying to knock your confidence or tell you that they think you're awful at writing; they are trying to help you pre-publication.
SO, if you receive an edited document and you're finding it all a bit overwhelming, here is a little advice on how to get through it.
1. Take a break once you've read the suggestions. It can be overwhelming if a story needs a lot of work, so take yourself away from it and go for a walk, make a cup of tea... anything to get you away from the screen while you process.
2. Every author is emotionally attached to their stories. It is normal to feel frustrated, or even a little upset, when you worked hard and then you get your manuscript back and see a bunch more work needs to be done. HOWEVER, remind yourself that every book you have ever read and loved has been through this process. The books you read did not come out that way. They are a product of a first draft, rewrites, critiques, and hours of caffeinated late nights. The authors you love felt the same things you feel, but they didn't give up, and you mustn't give up either. <3
3. Don't respond to an editor's comments when you're miffed. Don't even look at the work until you're calm because you won't be able to come at it with an open mind. To get the job done, you have to step out of your author head and into your reader head. Instead of responding with emotion, consider each thing with logic. Explain to your editor why you did things the way you did and see if they can see where you were coming from and advise you from there.
4. Take each thing a step at a time. Don't run yourself ragged trying to change things all in one go or rushing through it because you want it over with, because the chances are, you will miss something. Come at it with a clear head and the intention of only doing a chapter at a time. IF you happen to stay longer because you're in the zone, great, but don't force yourself to do it immediately and in one sitting.
5. Ask questions. A good editor will be happy to work with you and answer your questions. Also, editors are not completely immune to making mistakes or misunderstanding things sometimes. We are all human, and although it's terrifying to hand your work over to someone new, most editors aren't scary people with big red pens, ready to scribble all over your work! We just want to help you, so don't be afraid to reach out if something doesn't make sense to you.
All in all, the process of developmental editing should be taken as constructive advice for the strengthening of the story, not as a personal slight on the author.