I understand this. My early life was pretty bad. In my 20s, I got away from my family a lot more, and started living my life (mostly) how I wanted to. I'm in my 40s now, and I look significantly younger than most of my contemporaries. I'm not saying this to brag in any way. I'm simply trying to point out that stress and all those things in early life don't HAVE to lead to anything. They make us stronger, more resilient, and capable, as much as that sucks to have gone through.
Not trying to preach or tell you anything you likely don't already know, but as for exercising not feeling good, change it up! Find a new sport. Take a break from your usual workout. Start walking more. Look into yoga. Yoga is truly one of those things that everyone should do. It's crazy how much is affects your day to day. Everyone I know over like 30 complains about back pain, and I used to too. I have NONE (unless I do something stupid) after I started doing yoga 5 days a week.
Also, evaluate how you eat, and what you eat. I've started noticing A LOT more that what I eat the days before a workout have a much bigger impact on my workout than ever. I ate terribly this weekend, and yesterday, and my morning run was so much worse than normal today. I was dragging ass, and it was HARD, even though it was my mostly flat fast run (spoiler it wasn't fast today)
I'm in my 40s, and I'm still not ready to have grey hair. I'll keep dying it until I'm ready for it. As for the rest of the stuff people put themselves through, no thanks. I'm not trying to spend huge sums of money on treatments, peels, products, or plastic surgery.
I have a bunch of younger cousins who are like you, they just don't give a shit about it. They and their friends don't think it's required to shave their legs/pits. They aren't dying their hair, or any of the other things to keep looking younger. They saw they parents doing it all, and just don't want to participate. I'm a little envious of their no fucks to give, but like I said, I'm not there yet.