Get your book finished as quickly as you can. Don’t try to edit when writing. Then, afterward, do a self-edit to find as many problems as possible. However, that’s still unlikely to be enough. No matter how skilled you are with grammar, spelling, punctuation or other writing tasks, you still need to have another set of eyes looking at your book.
The expense of editing is normally beyond the means of self-published authors. Since my retirement from both the military and the ministry, I enjoy having a job that allows me to be available to my wife every day. Her auto accident in 2008 has made it virtually impossible for me to work in the public marketplace. However, over the past few years, it has given me a new career path that is very enjoyable.
If I can be of assistance to you in your writing, editing, or formatting needs, please let me know.