I am so tired...

Hey guys :) 
I hope you all had a great first week of school (or work or whatever, depending on your age), I think I just about survived!

It was brilliant to see my friends once again, even if I did have two assessments on the same day - history and science (I didn't mind my history so much, it's my science I'm worried about!). 
I have had a pretty productive week with lots of revision - I even managed to squeeze in a YouTube video!

One things that has been bothering me though is how tired I have been. What was so great about the holidays was that I got to choose my sleeping schedule, so of course I would stay up late and then sleep in till really late in the morning the next day. 
However, now I can no longer do that, and my sleeping pattern does not seem to be adjusting. My problem is that I am a complete zombie during school time, but as soon as the time comes for me to go to sleep, I am wide awake. 

This problem is not new to me - I have had problems with my sleep since I was a toddler and I would have night terrors. Then throughout my childhood I remember laying in bed at night, tired out of my mind, but 100% awake for no reason at all. I would go downstairs to the living room, where my parents would be watching TV in the evening, and complain, but they couldn't do anything for me. I think they wanted to help, but it really annoyed them at the same time. 

If I tell people about this problem, they always say "You should go to bed earlier", like I haven't already heard that advice before. I have tried that so many times, but I always end up lying in my bed for hours and hours, like someone has left a little light switch in my brain turned on. 
I have also heard some other basic advice, I know I shouldn't look at screens before going to bed or eat certain things, but I don't tend to look at screens before going to bed or any of that stuff. 

So this isn't so much of an advice post as a post asking for advice. Does anyone have any tips on how to get to sleep, or maybe do you have the same problem as me?
If you have any words of wisdom, I could really use the help. This morning I woke up up an annoyingly early time (it was, like, 9:30, which is early for me) because I am now used to waking up at 7, but I was still COMPLETELY EXHAUSTED. Just because my body is used to waking up earlier now doesn't mean my mind can cope with it. Last night I also read John Green till really late because I couldn't sleep.

Best wishes, 
Lucy x