Got back on ADHD meds that my parents took me off as a 10yo as they didn't like the side effects.
Exercised.
Study, get the certification I ended up getting eventually (that i was repeatedly recommended to do but was too perpetually exhausted to study for), and breaking into IT as a career sooner.
Not waste years 18-22 in a shitty grocery store/fast food job. To this day I can't stand to look at a rotisserie chicken cooker.