Serious question, /lit/: how do you sit and focus for long periods of time?

I am a 4th year uni student and I thought I would have this down by now but I don't. I literally cannot just sit and read-- I'm constantly fidgeting, looking around, spacing out, etc.

I try to read away from computers, I turn my phone off, I stay caffeinated--nothing seems to work.

When I was younger, I could sit and read a book from cover to cover without looking up, but these were fun books I was actually interested in.

A lot of the stuff I need to read for class (modern fiction, philosophical works) is pretty damn interesting but I just can't seem to fucking concentrate for more than a minute at a time.

Any advice/books that helped you with this problem?

inb4 ADHD
inb4 Retarded
inb4 minority