I'm in exactly the same problem. I've a real nack for history, and in GCSE I did well, and in learning it myself I do very well, however in A-Levels the method of teaching has just fizzed that fuse out. My Coursework is also due in by the end of the Week, so again, same problem.
I find the best way not to be distracted is to unplug everything, stick in headphones, have a bottle of water and just lock yourself in your room, create a bubble for yourself and work within it. Take regular breaks but don't "look forward to them". You know? Just focus on the work, and if you feel you've done a good amount, have a break then.
In terms of the Coursework, I too haven't started. However my question is one I picked, and is a question I'll do well at. First and foremost, plan the thing! Planning it is the hardest part. Make bullet points on every argument you're going to use, or every individual, turning point, etc. Then within the larger points, make other bullet points. Keep making notes, and break them down into the lines within a paragraph.
Once you've done that, the whole thing will just fall together like a puzzle.
Genuinely hope this helps, as I'm in the same pickle albeit in Year 13.
Still, you'll be ok.
Chin up, concentrate and you'll be fine!
If you've any questions, though, PM me or something.