Feeling stuck with low-paying clients

I have a series of low-paying clients that take up much of my 40-hour week, leaving me little to no time to work ON my business instead of always IN my business. Even if I do have some time available, I’m often so mentally drained from writing all day (I’m a content writer writing blog posts for other companies) that I have no energy to work on other things or write for my own business.

I feel perpetually stuck because I don’t have time to invest in growing my business, developing more credibility in my niche, and failing forward with my impossible goal. As a result, I continue with these clients who take up all my time. And I need the income they provide, so I can’t just cut them.

Ideally, I would like the time spent working on my business and in my business to be split 50/50. I know this is a thought issue, because everything is lol. But I’m new to SCS and am having trouble seeing how my model could be different. Here’s an unintentional model:

C= Clients pays me $xx per project which took (or will take an estimated) xx hours to complete.
T = I can’t drop this client because I need the money
A = I continue taking on projects for that same rate. I write on subjects I don’t enjoy. I spend most of my time writing and have no time or energy left over for my business.
R = I keep needing their money because I don’t land clients paying a higher rate.

Thanks for your insight!