I was just chatting with a friend and they made a similar observation. We used to devour books all throughout middle school and high school, but college seemed to have sucked that ferocity right out of us. I graduated 4 years ago, and I just haven't been the same since. It's funny, though. I read fanfiction constantly, but I just can't pick up an original book.
Personally I just have to avoid distraction; I don't have a smartphone but I have to leave my computer alone. Then I try and stick to a set amount of reading per day, such as a chapter in the morning and a chapter in the evening.
College did the same to me!! I read much slower now, but since my internship year, I’ve been able to read for fun again!! It’s hard to get started and I typically only read a chapter a day instead of consume whole books in one night or read non-stop until a book is done, but I’m happy to rediscover that joy. Good luck! Don’t hold yourself to past standards.
I’m sorry to hear that, but happy you’re recovering!!