Finish reading Stephen King's Dark Tower series

After a long delay, I read Wolves of the Calla. I had it and could have read it sooner, but thats another story. Anyway, it was good, and I am now a little over halfway through Song of Susannah. Im enjoying it, so so far so good.

I read the first 4. Then my girlfriend got me #5. She felt bad and overcompensated, so thats why she got it for me. A month later we broke up (we were together 2+ years). I cant read it because I connect the book with her, and I dont want to do anything that reminds me of her. So it sits in my room collecting dust. Literally.