If you're not excited about what you're doing, the kids will not be either.

There's a lot going on in education right now (or rather, not going on in education anymore right now) that probably has a lot of people losing confidence that teaching is "for them". I hope that's not what you're experiencing, but it could be that as well.

I always try to do some type of staff development in the summer which can consist of:

TBA
Attending professional concerts
Conn-Selmer institute stuff
Teacher prof development such as SHSU

You've got enough experience to know what you want and maybe be depressed about it, if it's not there yet. Then again, years ago you didn't realize how bad things might have been at the time.

You may even want to consider a change in positions. The TMEA job board has many postings daily. Sometimes a new job creates new challenges - variety is the spice of life.