We all have problems, challenges, struggles: it seems natural for anyone, regardless of how well their basic needs can be met, to suffer. I feel that we easily make trouble for ourselves, and that too many of us have it too easy, which ends up being rather difficult.
Some actions that have helped me (I'm in my 40s, male, an at-home father supported by my spouse to care for our child with disabilities, and I have no significantly-debilitating health concerns):
Breath-holding practice: the most afraid I've ever been (that I can remember--perhaps something worse happened when I was very young) is when I was underwater and a trainer grabbed my leg to keep me under (all part of the test; consensual on my part). I was not ready for that sort of work, and I opted out. The experience sparked something in me, though, and I've since worked on my breathing so I'm more and more comfortable going longer without oxygen, and so I'm generally well-oxygenated and well-regulated (see book Breath by James Nestor and Breath Taking by Michael Stephen), practicing many times throughout the day to inhale over about five seconds and exhale over six or so; helps against anxiety.
Going longer without food: another opt-in stress, rather than being subjected to it, fasting has recalibrated my relationship with food. The old grooves of eating to escape emotions are still there, but I can manage much better now that I've gone more than 60 hours without eating and am ramping up to go longer (taking it slow so as not to disrupt my parenting and homemaking responsibilities). This is after a couple months of practice, after years of dabbling and being aware of fasting as a thing but not actually committing. I found the book Life in the Fasting Lane, by Dr. Jason Fung, Eve Mayer, and Megan Ramos to be helpful. Fasting will keep you hungry at first, and then you'll be able to ride the waves of hunger, let them swell and ebb, and get into a focused "hunt" mode. If you go long enough, beyond about 48 hours when autophagy kicks in, you might find yourself waking up clear-headed (I do, anyway) and with less pain (at your age maybe these aren't concerns). I'm now comfortable with a single high-quality meal each day as a baseline; there's no room for less-sustaining foodstuffs that have a lot of sugars, in part because I am now more aware of what I feel like after eating junkfood. Same with alcohol--I occasionally have a sip out of curiosity/nostalgia, but after a couple years away from it the benefits are far outweighed by the negative consequences. I don't miss it.
Doing one thing at a time: Like with fasting, I've known about and dabbled with meditation for years. Only recently have I started practicing doing just one thing at a time and being okay with missing out on also listening to a podcast or audiobook or music while I wash dishes, for example. When I go out for a walk, I'm rarely listening to anything anymore, and letting my mind freely associate. I tend not to practice the increase-time-between-thoughts meditation, and mostly practice being present with whatever I'm doing. This is both important for me and for my child when we're playing together or I'm reading aloud or we're outside exploring, and so on.
Reading old books, and books about other cultures: Don Quixote is more than 400 years old, and it's clear we haven't changed much. This perspective helped me relax and accept this life, this story I have a hand in writing, and that my book will end. Reading The Old Way by Elizabeth Marshall Thomas opened my eyes to the stresses of hunter-gatherer life (for example, women in the group she visited only menstruated when there was enough nutrition available). I feel that if we still lived like that life would not be easy but we'd also have fewer of the struggles you're describing. There would also be fewer humans, which feels appropriate given how much we have changed life on Earth.
From The Blindboy Podcast (instrumental in my mental-health-improvement journey): "You are better than no one, and no one is better than you." The best time to make mistakes is during youth, and then keep making them and adjusting! I haven't fully internalized this yet, being a perfectionist much of my life, but I'm increasingly willing to risk looking like a fool to myself and others. Parenting helped open that door but don't think it's the only way. Blindboy's point: decouple your self-worth from your actions.
Pick a thing to get really good at: For me it is bicycling; I've spent more than ten thousand hours on a bicycle, mostly for transportation. Having some idea what it's like to get so good at something helps me choose how I spend my time. When I play videogames now it is with the understanding that I could be doing something else ("ideally" reading) but that this current obsession will run its course. Regret isn't helpful. Considering what my future self will think is helpful, and in times when I just want to zone out in videogame-flow (a weaker form of creative flow; feels like flow but I can feel hollow afterwards rather than full and refreshed) I do the more-difficult thing and sit with my emotions awhile, then either consume something healthier (reading or watching something that helps me grow) or practice creativity through writing, drawing, humming, or any other art.
Good luck!