This is a very tricky question, TJ, because there are so many possibilities. The first thing I would ask you is to try to identify a trigger that shifted your feelings. Did it happen suddenly? What does it remind you of? Do you feel too safe? Did the "crazy in love" excitement become too "normal"? See what you can come up with so that you can decide how to proceed. Sometimes our reactions are coming from a healthy "this isn't going to sustain me in the long-term" place; sometimes they come from less healthy or desirable places (like realizing that you need chaos in relationships to stay interested, which doesn't bode well for you to be committed for long!).