Cognitive problems despite the young age
It is very disturbing. It's difficult for me to recall the right word. For example, I can remember a story, but can't find out who is this story about. That happens all the time. I read a lot and forget all that I've read very soon. I forget to even those things that I've been emotional about. I can't recall even the simple things that I've studied in a school as well. I am very, very absentminded: I am someone who can get on the bus and go in the opposite direction for a while.
All that happens even though I will be only 19 soon.
I can certainly say that my memory was much better, as well as my willpower. My depression started about more than 2 years ago, triggered by the huge stress in my life. Also, I have a schizoid personality disorder (been diagnosed as a schizotypal, but I think I have not enough symptoms for this one).
I have a lot of problems, but being not able to study is the most disturbing for me. I lose my motivation when I try to study something new and just forget everything. Now I am not in school nor at the university nor do I work, and I am extremely lonely. Add to this that I have problems with the law (drugs) and chances are I will go to jail.
I still have hope. I hope that I will be able to study again and become a scientist. I hope that I
@damocle
Hello ! 
Firstly I think the advice of a doctor would be the most fair and useful for you.
I am sorry for all the difficulties you encountered. I will try my best to give you some advices, I hope it would be a little helpful !
You have hope is this is the most difficult and the most important step : you can be proud, because this is the key to get better.
Adopting healthier habits, perhaps by setting schedules. Especially relaxation times, which could be resources for you to face the rest perhaps more easily.
A schedule for waking up, studying, eating, resting, sleeping... It can be frustrating, but once you get used to that, it becomes easier and more effective.
Turn on music when you wake up during your tasks... Enjoy a delicious breakfast, treat yourself. Try focusing on the present action : what do you feel doing this ? What is the positive aspect of it ?
A significant motivation for the times of tasks and work and to compensate with something pleasant : drink a coffee, wear your favorite cloth, listen to music, smell a pleasant perfume... And also a to set a reward : "after this hour of study I could : have dinner, go outside for a walk, go on YouTube..."
You are already making so many efforts. It's amazing, you are on the right track. 
For your leisure time, doing what you love is important. Also, mindfulness meditation exercises can be very useful for you : they allow you to center yourself, to relax intensely, to feel better, and also to improve your capacities and many other positive things. Here is an example of an easy and quick exercise you maybe could try : (only 3 minutes) : https://www.youtube.com/watch?v=SEfs5TJZ6Nk
For your sleep, achieving many things during the day, sports can help you sleep less and sleep better as you do, and of course a healthy lifestyle too. Putting sleep schedules in the same way can support you to gradually reduce your sleep time. Slightly reducing the time each day will be much easier and more effective in the long run than trying to reduce all at once.
Concentrate on your progress already present : it's amazing ! 
I am here if you ever want to speak in private chat, I would be glad to support you. Take care of yourself, goodbye.