First thing - don't search for motivation or don't try to get yourself motivated. You'll end up looking for things that will make you feel good which will in-turn promote procrastination and thereby take you away from actions. The truth is motivation doesn't last. It's a push mechanism. You'll have to focus on things that pull you towards it.

If you keep going like the way you are currently, how would your life be? Definitely you understand the problem with it and this post is the proof. But ask yourself - "why do you want to get A-levels at school?". If programming and researching keeps you going, by all means, you should focus on it. Make sure you put the best possible efforts in it; the rest will follow automatically.