Are you kidding? 13lb is pretty amazing. It's no little feat. Stalls are really annoying, but I think they're kind of a test. An annoying test lol. Are you also using at tape measuerer? Some people notice they're losing inches even when the scale isn't moving. Give it another week, and if there's no change, maybe you could tweak something. I'm not familiar enough with SBD to suggest anything, though, but maybe someone else can.
Most importantly: don't give up! If I hadn't stalled and decided to maintain for "a few weeks" or "a month," I might be looking at a different number on MY scale right now. Just keep at it.
Also, congrats on the loss, and great job.