Interesting. I felt like you at age 25, when I was hit by poverty, uncertain direction, and health problems.

I'm 28 now, and feel like I'm getting younger as I age. But not quite as young as when I was 21. There's definitely aging there, I think.

The three things that have produced the biggest impact for me have been:

  1. Barbells 
  2. Mindfulness + stoicism (Seneca)
  3. Finally earning a good amount of money

The first one was the easiest to implement. Have you tried barbells?

Mindfulness I only really managed after a health crisis forced me to deal with the stress constructively. Money I can't advise on.

But barbells are very easy to implement. Takes me about 30 minutes, three times per week + a $40 gym membership.