Writing time versus marketing time

It's a common complaint by authors, whether traditionally published or self-published. How much time do spend writing and how much time do you devote to marketing? Everyday I receive another email pitch for a course that tells me how to sell more books. Some are very valid, like those from Mark Dawson or Dave Chesson. Others are simply time wasters and time, believe you me, is vital element to manage in a writer's life.
I've still got to finish my surrogacy thriller MISCONCEPTION because months ago a few agents expressed interest. I thought I'd send them the first 19 chapters and hope I'd get a positive response. Instead, nothing, except one saying she wanted to read the full MS. Without interruption I can easily 2,000 words a day (or a morning) but interruptions are the bane.
But learning about Facebook advertising, building a mailing list and Amazon ads has taken time, which means time management is critical. In theory I write in the morning and market in the afternoon but then normal life intervenes with family matters, holidays and chores.
You can see my first attempt at a Facebook ad for THE IMMORTALITY PLOT (which I also have had to restructure and redesign the cover) and it all takes an inordinate amount of time. Luckily, I have spent a career in PR so this does help.
And then there all my other books to consider. 
And then there is life and living.
Keep the faith.