<human>: I have been with my BF for two rollercoaster years. We started off great, I was so happy to finally meet someone I was very compatible with. However things started becoming less shiny over time. We've had our fights and breakups and through them I was convinced I still love him.

However, recently I no longer feel that strongly. After our most recent blow out a month ago, I demanded that we either go to couples therapy or work on our communication through a book. He balked at the couples therapy suggestion but agreed to get a book. That was a month ago and he still hasn't gotten the book. Obviously it's not about physically getting the book, but feeling that he is willing to work on the relationship more than just going out with each other and having a good time. 

I just feel so unsatisfied. And while I love him as a person, I don't know if the romantic love is still there. I went away for a week and he remarked on how happy I looked on my return. And I was! When it came time for sex, I just felt...nothing.

I don't want to nag someone into change and I feel bad about my shifting feelings. But after 2 years I just don't feel this relationship is moving anywhere. It feels stuck. Is this something worth working on? Is it temporary? Please help, the limbo is annoying. I do love him but I know that love isn't enough. I'm not even talking about engagement or marriage or even or living together. Just some show that we are getting stronger.

Condense the text into a few key points
<bot>: Been in relationship with lover for two years. How do you know when it is a normal lull vs time to pull the plug?