I wish I had a good answer for you. All I can really offer is commiseration, by way of saying that I have the same issue. I spread myself way too thin, trying to work on multiple projects at the same time, instead of picking on and working on it exclusively (or even near exclusively).

That said, to the extent that I have gotten any better at this over the years, I did the following:

I created a page on my personal wiki, with a "todo list". At the very top, before any of the todo items are a series of questions. Every time I look at the list, I'm reminded to ask myself those questions.

I don't have the list in front of me right this second, and I'm not sure I'd want to share the exact list anyway, as it's kinda subjective and personal. But assume it includes things like:

1. What is the single most important thing I could be doing RIGHT NOW, vis-a-vis creating revenue?

2. Whatever I'm about to do, WHY am I doing it NOW?

etc.

It helps a little bit, but not completely since so much of what I do is kept in my head and I don't consult this page all that often. But at least I get a little reminder every now and then of what I'm supposed to be focusing on, in terms of the strategy I wrote down.