What’s it all about?

My brain is foggy, and my enthusiasm is at an all-time low. Over the last twenty years, I’ve invested many hours into writing. It has been a twenty-four-seven-hour job. If I’m not at the keyboard; it’s been time used thinking about the next writing project.
Yes, what right do I have to complain when I’ve had some success, with six books in print, but it’s all about sales. I’m nowhere near where I want to be and feel like I’ve hit a brick wall. I just can’t see over it, around it or under it. It’s not writer’s block. I’ve got plenty I can write about, I just don’t know whether it’s worth it anymore.

I’ve just spent the last twenty years mastering the skills necessary to write, but now it seems that’s not enough to generate sales. What I need is a large sum of money to promote my work. I have a blog, but an increased number of followers are just people offering services to me, LinkedIn and other social media platforms are hunting grounds for the same type of followers.
It’s as if everyone has services they think you need. There are new writers wanting you to buy their book in exchange for a review of your book. Reviewers flood my email account with amazing offers. They tell me they have numerous numbers of eager readers waiting for my books, but nothing is for free. Paying for reviews isn’t something that sits comfortably with me or Amazon.

Who am I writing for?

Writing for the love of it is great advice, but without readers, I might as well write and post my work here for free. Now we have AI writing too in a flooded marketplace. It just feels like I’m adding to the flood when I could be off doing something else with the time I have left on Earth.
I’m just feeling a little lost as I have nothing to compare my success with.
Am I just kidding myself or am I moving in the right direction?

Is selling twenty books in a year good or bad?