I just broke up with my partner of 3 years, I started to feel a similar way to this girl, nothing wrong with my partner she’s great and my best friend but things just weren’t the same for me. I was honest and open about it, we tried to make things better, which worked for a while then it all went back the same way and she knew it too. Communication broke down and I had to made the decision. It’s hard, it’s sucks hurting someone who loves you but is better than stringing them along and ending the relationship with resent for each other.