Sometimes, we're in love with what something used to be rather than what it currently is. MA, significant others, jobs, etc. We think those things that initially attracted us to it and kept us at it for a long time will come back. We can be more in love with the past and justify keeping at it presently because of it.
When you know you've given all you had, and have taken all you can, and there's no passion left, it's time to move on. There's no point practicing an art when you're there solely because you've been there for so long. There's no point in practicing an art that you're not fully committed to. Life's too short. Sure, we all have our bad days when we question why we're still at it, but if those days are the norm rather than the exception, it's time to find something that brings back that passion. Otherwise, we're just going through the motions. That's not fair to ourselves, our teachers, our training partners, nor anyone else.