I think if you feel it is something you need ,you should do it. Now is actually a good time being in-between things. In fact you can tell future employer that you want to take a couple weeks of vacation before you start. It is better than getting started with clients than having to take a emergency leave of absence.

Maybe your T feels like he should be doing something more for you to prevent this, so maybe there is some guilt there and loss of pride over his best client. Good luck...