Espada

For over a year I have some problems with my sleep cycle which I can't fix it. I will use a 24 hour system to explain it.

I go to sleep very late (the time varies from 00:00 to 03:00) everyday. And I wake up also kinda late (everyday, I wake up at a different time, from 10:00 to 12:00). Yes I sleep for 8 hours or more. But It's very hard for me to wake up, I feel very tired, like I did some major exercises, which is not true.

Before going to bed I stay at the PC for hours, then I jump to the bed. I don't eat a lot for breakfast, and I don't eat a lot for the entire day.

I'm 24 and I weight 65 kg (143 lbs) and I'm 1.80 cm (5.91 ft) tall.

I tried to go outside and do workouts, going to the woods and trying to stay outside and use a lot of energy to feel tired at night so I can sleep earlier, well that didn't work. I went to bed at 23:00 and I stayed awake just changing positions for hours, I picked my phone at It was already 03:00 and I still can't sleep.

I want to change my habit... I want to wake up at 06:00 and go to sleep before 24:00 because in two weeks I'll start to work in a new company which requires to start early... and thinking about that, i'ts impossible for me to wake up so early.

What should I do? Please, help.