I'm not a fast writer. I can't "sprint". I've learned that my writing becomes flat and mechanical when I do, because I don't feel any more. Everyone has their own pace and I admire (and am more than a little jealous of) those who can write 2,000/5,000/10,000 words a day. If I can get 500 words a day, I'm good. If I get more, great. If not, I don't sweat it anymore.
I was actually burning out over the last few years while also maturing in my skills. It was a struggle. I've learned the many reasons why and made changes that are helping me. Part of that was finding the pace of writing where I was comfortable. Another part was having a terrible weight lifted from my shoulders that was increasingly pressing me into the muck of despair. Freeing myself of that burden has freed my mind and my creativity.
While these changes can't save the slipping sales of my present books, I'm no longer dependent on those sales for paying my bills. I have a part-time job where my skills are challenged, I can use my creativity and experience, and I can make mistakes without feeling miserable...not that I want to make mistakes, but I don't have to be hard on myself when it happens.
It all adds up to a happier me and that means a freer mind, which translates into having more fun writing again.
I've also been blessed to recover my family time and that has me feeling even more fulfilled. It's the little things in life that make it worth living. We don't have time to suffer in misery. I'm not worrying about ebook sales any more either. Rather, I've been able to appreciate what I have and stop trying to be competitive once and for all in trying to do what other writers with lots of sales were doing. THAT was the final thread holding me back. I can finally be myself again.
I have rediscovered who I really am.