What does one do for apathy?

I’m just not showing any interest now.

The old “shot in the arm” doesn’t work in the long run.

I have been struggling with this also. I need a hobby. Right now I’m going to read some Philip K Dick.

That’s a tough one. There are many things I am ambivalent about. One solution is having an emotional attachment toward something, or in my case, someone. My daughter. One would think that such an attachment should be natural. A given. As it turns out, it isn’t always the case.
Mostly, I find that the frustration level with any interest is a major factor. It can either drive my focus or drive me away.
You may find yourself with many interests but no standout driving passion. Pick one for a while and follow where it leads.