As long as you hand over total control of your happiness and mood to other people, complaining about how you feel while under their total control makes no sense because its not your responsibility, you gave it up. The other 11 steps of the 12 step programs are off topic and probably some are wrong anyway, but surely you'll never conqueror your problem until you admit you've handed over control of yourself to something (someone) that doesn't necessarily have your best interests in mind, and unsurprisingly its not going too well, at least for you. So good luck with that step, first.

Also you're not older, you're just a kid with kid moods, which is perfectly appropriate when you're a kid, so... good (edited to emphasize, good as in there's nothing wrong with you, not good you're unhappy). You'll know you're actually old "for real" when your self doubt switches entirely over to "Why did I waste my life on screen time, doing stuff I don't care about to earn extra money I don't need to buy stuff I don't want to impress people I don't know who won't care anyway, when I could have been doing something meaningful like (playing with the kids, watching that eclipse, climbing that mountain, dating that person, taking that class, learning that skill, reading that book, watching that live music event, building that thing...). All I really remember from the youthful age of 26 was the fun of dating my future wife and to my regret wasting too much time on work and business and computers, its the mood switch that's how you can tell I'm old(er), not necessarily the memory loss LOL.

There are also serious educational issues, looking at something like the greek philosophical ideal of balance being the goal and lack of balance inherently being wrong in and of it self, I can assume if you're only freaking out about financial success and fame, then your musical listening and instrument playing is going really well, you're reading some cool lit, and you're up to date with exciting recent developments in philosophy and science, eating great food, exercise is going well, and all that other "well rounded human" stuff. There are Eastern outlooks that say basically the same thing with totally different words. Seeking balance seems an almost inherent part of being human. So you didn't get a good education, even if you got excellent vocational training or on the job training. The only way to make that bad situation worse is to not work on being more well rounded.

Note the common mythological trope of some dude who focuses entirely on one thing, gets really good about it, and ends up having a really shitty life (struck down by lightning by the greek gods for hubris, chained to a boulder while vultures eat his liver for all eternity, wings melt in the sun and drown in the ocean, etc). I think the ancients might be trying to give you some life advice about the inevitable result of deciding to be a little too focused on one aspect of life.

So best of luck, you're very young and have plenty of time to figure it all out. It would be way more tragic if your post claimed you're 62 instead of 26 and you're just starting to figure out life. You'll do fine if you're already that far at this young age.