Anecdota about depression and exercise:

It’s not getting in shape what lifts depression, it is physical activity in itself. You generally feel better after exercise.

It becomes much easier to hit the gym after realizing the reason to go is simply to feel better. Instead of thinking I don’t feel like going to the gym the correct cognition is my medicine is there.

There’s a variety of options to exercise. Don’t stick to running if you don’t enjoy it (but you keep doing it because you feel better). There’s a large menu of activities, at first try what is convenient, deliberately try many things and find what is more fulfilling to you.

With exercise nutrition follows quite naturally. It’s difficult to navigate all the BS in nutrition, but in general eating fresh things closer to nature (leafs, fruit, veggies, nuts, lean meats) also has an impact on your wellbeing.

Often there are more issues other than lack of exercise. If you are socially isolated, if you are under constant stress, if your home situation is dire, exercise will help you cope with it but it’s not getting at the root cause. Identify and work on the cause too.