I went through this exact same scenario. Late 30s, recently diagnosed. Couldn't hold a job more than 2 years because I'd get bored/burned out really fast.

The way I did it was similar to what you've already done except I started doing yoga and jogging as well. It helped me stay calm and think clearly when combined with meds. If you haven't tried doing yoga, don't sleep on it.

If you work in IT, look into MSP work. MSPs can be tough but they often have lower barriers to entry due to high turnover. If not, there is probably something similar in your field.