I've been reluctant to jump into this but I can't stay silent any longer. And this is NOT directed at any one person. It's a general post. The more you take rejection personally, the less you'll learn from it and grow as a writer. The worst mistake any of us can make is to believe our writing is already perfect and no one can help us improve it. Between my three pen names I have nearly 70 books published and you know what? I learn something new each and every single time I write another one, and each time my editor sends one along for revision. Every. Single. Time.
The publishing world HAS changed. Drastically. Agents and editors are no longer the only gatekeepers. People self-publish and self-edit, but guess what? That doesn't mean the writing is stellar. Unfortunately, MOST of the time it's pretty darn bad. Is every editor 100% correct? No. But learning the basics - learning the craft - is part of this game.
Agents and editors are in business to make money. If they don't believe they can sell it, they won't take a chance on it. Period. End of sentence. That's how the world of traditional publishing works and that's also why so many thumbed their noses at it and self-published.
My own writing is not perfect, nor will it ever be. I'm human. I accept that. But I also work very hard to constantly improve it. I take every single review to heart. Even the bad ones, and you'd better believe I get them. I take every single suggestion my editor gives me to heart. I may not change everything to suit her tastes, but we're talking fine points here, not glaring errors or sentence structure oddities. And as for reviews, even the mean-spirited ones often (usually) contain a kernel of truth.
So honestly… if you can't see the errors or faulty flow in your own writing yet, you're not ready to submit. And if you refuse to take critique about that, or refuse to put in the work to improve your writing, you're going to find this is a long, difficult road.
By all means keep writing, but buy, beg, or borrow some craft books. Take classes. Pick apart the books in your genre that you love to figure out how that author did it. How they pulled you into the story and kept you there. Try to emulate (not copy) that, then develop your own style. Find a beta reader. Not someone who will tell you what you want to hear, but someone who has been there and done that, and will give you no holds barred HONEST critique. And then be a strong enough person to take that critique and use it to improve.
Hope this helps. It's not meant to be mean, but merely honest.