I've got something similar going on, except lately it came to a point where my "obsession" had started changing daily almost, and it was similar to how you describe it, being into one subject, believing that's my passion what I want to do from now on. And the next day dropped it and there was another one and so on. Signed up for countless tutorials and online courses I never watched. Also my belief system and worldview was changing all the time.
It ended with me getting very depressed and now I'm sorta not into anything (well, not true, now I'm obsessed with psychological articles and movies maybe).

In my case I don't really know what I believe in aymore. Also want to change careers (had done that several times in the past because I cannot stick to something for long, I lose interest and get even repulsed by it) and no idea now in what direction to go, as you said what to invest in, because I know it will change.

I initially thought this was BPD related in my case, but regardeless, I've been trying to accept as part of my personality. Though yeah, I don't know if I can just accept it so easily.

But in the same time our society is built up in a way that people like us feel like there is something wrong with us. But maybe there is nothing inherently wrong with switching interests all the time. Maybe it's even more natural than being into the same thing forever. I don't know, I'm trying to see more sides of this...