Brace yourself, Johnny, what I am about to say is dead serious: you almost certainly have ADHD.
I smoked two packs a day for 26 years. I also read novels my entire life, anywhere from 2 to 6 every month.
I quit smoking in September 2000. Cold turkey, no patches, no nothing. Since that day, 14 years ago, I have read exactly one novel. Starting on that day, I stopped being able to read novels, or any longform writing requiring linear consumption.
I told my then therapist about it at the time, and she suggested that I had ADHD, Because ADHD is treated with stimulants, and nicotine is a stimulant. A stimulant that has been shown to be effective in about 10% of ADHD sufferers. I had been self-medicating.
I dismissed her suggestion at the time. But over the next five years, as the other symptoms increased in severity, (symptoms which had been present my whole life, And were the primary source of all of my struggles in life) I continued to seek help with my struggles. I had a telephone conversation with a potential therapist, and after describing my issues, he said “you sound like you have ADHD, before you and I start any therapy, I think you should be evaluated by a psychiatrist”.
And so it was that at the age of 47, I was finally diagnosed with ADHD, which had only been suspected when I stopped medicating myself with nicotine.
That was almost 10 years ago, I have been medicated ever sense, and Unfortunately for me none of the standard meds are effective for me when it comes to reading books, but they help in other ways.
I strongly urge you to make an appointment with a psychiatrist familiar with adult ADHD, and get evaluated.