When you start therapy, talk to your therapist about books that you write in. Maybe it is a workbook about what you like to do. Maybe the physical Act of writing in a nice moleskin notebook book that actually looks like a book will help you with desensitization. Or puzzle books. Or books where you color or reverse color where there are colors and you draw the lines. There is a book series called burn this book where the purpose is to deface the book that you have bought and that might be another idea.

As others have said, you are on the right course, I am sorry that other people made it sound like you are having these problems because you just haven't found the right book yet.

As an experiment to yourself, you might also try writing something on paper and then reading it back and see how you do and if it triggers your OCD ticks or if you do okay. This will help you to think about what things specifically are triggering the ticks.