I’m not quite sure whether this is right or not, but, here you go!
a. You can exercise more often or do a bit more throughout the week/day.
b. Eat a balanced diet, so don’t keep eating unhealthy things all day, but don’t constantly eat healthy things either, make sure it is actually balanced.
c. Spend more time outside. This can make you happier, lighten your mood, and it could motivate you to do more exercise.
I really hope this helps, but if it doesn’t, I’m very sorry I tried my best!! :)