I don’t force myself to finish books that I’m not enjoying. I used to do that and it resulted in a reading slump every single time.

I log it as a DNF in my reading journal and note how many pages I read. I don’t rate it, but I do write why I decided not to finish it.

My only suggestion is to figure out a time of day where you almost always have time to read, and then read consistently at that time. Even if it’s just a few minutes each day it will become a habit. It could be after you wake up while drinking coffee/tea, or during a lunch break, or right before bed. The key is consistency.