First off, if you want more discussion on you, the Life Advice board one below this one (General Discussion) is a particularly apt place. I know it helped me feel better when I was in a horrendous slump about a month ago (writing there was always a relieving moment of the day during that time).
Second, I've done the same sort of worry about if my problems aren't things I shouldn't be worried about, if I really should just suck it up and move on. I think one thing you should remember is that
if it is hurting you, it's a real problem. It might not be as objectively terrible as not having access to clean water, sure, but it doesn't mean your feelings are invalid (you should use the fact that calling them "first world problems" hasn't helped you as proof of this). It's healthy to be critical of your problems (instead of just relishing having them, being able to play the victim), but don't try to invalidate them.
For what it's worth, I've thought about past me and future me a lot as well. In fact, during Season 32 of Doctor Who I could swear that future me must've been helping the scriptwriters steal my ideas, although that's likely something totally different
.
And, considering the writing of your rants, may I suggest creative writing? You seem incredibly prone to creating good metaphors for your state of mind at least
. And no, your stories don't have to be apocalyptic because that's how you feel. Write about the most cheesy, unrealistic, idealized life you could possibly want to have. The saga of Earth's inhabitants preparing for
the next pole reversal. The tale of the CIA/MI6/whatever agent somehow tasked with assassinating the governor of Nebrahoma.
My point is, I have a fleeting suspicion writing of some form would suit you.
Wish you the best, Cmega3.