Yes. I've been writing professionally for a very long time - first short stories for women's magazines, and much later, novels for children and Young Adults, with Walker Book, Random House, Simon & Schuster, Hachette etc etc Still doing it in spite of the fact that I'm ANCIENT!
Decades ago, I did join a local writers' group, which I used to keep me working at a long adult novel by convincing myself I couldn't turn up at the weekly session without a full chapter tucked away. The woman who ran it became a friend, until she went back to America and we lost touch.
I have never self-published, but I have professional colleagues who have, and they are excellent writers. I have never entered a writing competition. As someone on here has already said, having a good editor is like gold dust, and I was amazingly lucky in that respect.
Join the Society of Authors - pricey, but worth it. If you're female, look into MsLexia, an excellent magazine for women writers. If you make it into traditional publishing, be prepared for book death, or being out of print - almost as devastating as an actual bereavement. Do it for the joy of doing it, with no expectations, is the healthier way to go. Good luck anyway.