I'm going to be the one to disagree. When I stopped working and just playing to play, that was the end for me. Slowly but surly my playing ability slipped away. It took a long time and hard work to get it back. I do agree to sing and have fun while performing. Just make music and enjoy listening to yourself. As far as not progressing, I would think about changing teachers or looking for a different approach musically. When I got back into playing my new teacher changed everything I was doing musically. My whole idea of what things should sound like changed. My teacher might be in left field but the idea is that he opened my eyes to see things differently. It's kind of like looking at a painting from the left and someone says "look at it from here and tell me what you see". Same picture, different view. I think that is how not to get stuck and stale.