absolutely. try and recognize when you're having those thoughts, and saying "ok. i am reading now" is a mindfulness-oriented recognition of what's occurring without passing judgement that you arent doing enough/are falling behind. most of all, be gentle with yourself.

op, if it's worth anything, none of the books you read in high school are going to be books that other people havent already read and written up exhaustive summaries or papers on. when i was really struggling, i would try to read sections of the book, and if i was really having trouble with a stretch, i would let myself move ahead 5 pages. at the end, i thought about the plot and themes of the book, then reviewed a summary to make sure i understood it as it had actually happened.