I agree with the rest of the thread, its probably depression, or something that aligns with it.
Especially with the way you phrase it, it sounds like boredom of life almost.
I used to think like that a lot, but the one thing for me that got me out of that was simply doing shit just for doing shit.
Like going to watch a movie just cause you feel like it
Doing anything not even because you feel like it, but because you just thought about it.
Like genuinely, think about doing something fun, and go do the first thing that comes to mind tomorrow.
Also this is going to sound really fucking bullshit, but go walk. Like just put on some music and go walk for like an hour or two, just thinking about stuff. Try to go to places that you find beautiful maybe, thats what I do but I live in a really nice walkable city so its easy for me
Going walking is pretty much effortless, and just walking around and watching people have fun puts me in a good mood usually.
But yeah, this really just sounds like a big downwards mood swing, and even if its not depression, you are definitely having depressive thoughts. You should be having fun with life urgently !!