38BB doesn't sound like much of a downswing. I lose my stack all the time and I don't give it a second thought. It's usually happens on the best tables too, where loose/maniacs go all in with flush draws, TP weak kicker etc. I just rebuy and continue playing.

My worst downswing so far has been about 3.5 buyins=350 big blinds (175 big bets). You just have to accept variations like this.

Sounds like you are playing limit, though. But from what I've read on this forum, limit has even bigger swing than NL. So, a loss of 38BB should be even less of a concern.