I agree with Lisa, completely. When I had my editor they were a godsend to me, but unfortunately I lost them because of the workload.
I have since had trouble getting another one.
Again, I blame myself. I fear editors even though I know I shouldn't. I have to be careful to balance my need for excellence with my confidence to go on. I think many new writers find the tension between these two things difficult to manage. I suppose that is what separates a successful author from everybody else. But fear of failing is the author's bane and the editor holds the power to help an author through this or kill them creatively, hence the fear.
So, I suppose a suggestion for a next segment of this invaluable series would be 'How to attract and keep an editor'.