Keeping track of your own 'score' could be really helpful in situations where you are not mentally stable, but you don't know why. The things to keep track of are the following:
Hours of sleep per week
Hours of screen time per week
Hours of any physical activity per week
You want to try have your score as following:
Your sleep should be over 50 hours per week
Your screen time should be under 30 hours per week
Your should exericise over 5 hours per week
If any of your these scores don't match what you are currently doing, that could be the problem. If you have a problem with matching with these, then try these tips:
Try to go to sleep 10 minutes earlier everyday until you sleep enough per day
Reduce your screen time with 10% each day until you reach your goal
Go outside and take a walk in the park or something similar until you reach your goal
Doing this will hopefully help you finding the reason for your mental ill.
Of course, there are other reasons for mental illness. To learn more, follow this page: