Could lifestyle changes improve brain health?

Hi doctor,

I am turning 22 in two weeks, and I am deeply worried about my brain health. On the top of pretty moderate to severe inattentive attention deficit hyperactivity disorder (ADHD) and general learning or processing issues, I smoked way too much weed from ages 16 to 20. For all of my life, I spent most of my leisure time zapping my brain in front of the tv or computer due to extensive depression. I did not take part in many hobbies growing up either. I have a pretty good understanding of neuroplasticity, and I can see how these habits have damaged my neurological and thus general, potential. My question is, does my brain still have a chance to be adequate and powerful? I only have three years left of profound brain growth. I live very healthily. I eat small portions and include periods of intermittent fasting. I am currently on a ketogenic diet (no sugar or carbohydrate, high fat, protein and greens) and I exercise high-intensity cardio and weightlifting for three to five times a week. I am doing meditation every day for more than 10 minutes almost for a year now, and I am beginning to engage in meaningful activities such as salsa, yoga or tennis as well as attempting to build friendships and reduce stress levels. Could fundamental lifestyle changes such as the above give a neurological advantage compared to those in my general demographic? Thank you so much for your help. It means a lot.