I seem to have a hard time focusing unless I'm doing something. Sleeping is difficult for me, it's like a torrent of thoughts, heart racing, that sort of thing. I'm doing online courses obviously and I can't help but start spinning in my chair, drawing stuff, looking up things on the internet. Reading books is difficult because I can keep going over the same paragraph as my mind wanders. The thing is that i can become super focused on certain things, including drawing and doing math problems. I can spend over an hour sitting there drawing a ship and be completely immersed. Same goes for math problems. Can't tell if it's willpower or maybe ADHD. What are some signs? How do I deal with this?