If you get up late, you will rush to school/work.
If you rush to school/work, you will forget this and that.
If you forget this and that, you will feel less confident.
If you feel less confident, you will perform poor result.
If you perform poor result, you will feel unproductive.
If you feel unproductive, you will feel sad/depressed.
When you feel sad/depressed, you will stay up late.
If you stay up late, you will get up late.
So my advice is set regular time sleep and get up.
A healthy n happy mind can be caused by self-motivation and 1 simple thing u can do is to challenge ur mind filter by writing down 3 good things that have happened each day n praise/reward urself for making them happened...Be proud of urself!!!