Since starting a new probiotic i have been feeling very anxious a couple hrs after. could a probiotic cause this? is it reason to stop taking it?

Perhaps indirectly: There is evidence that probiotics can help reduce anxiety. I haven't heard of them causing anxiety but perhaps they're killing yeast and unfriendly bacteria in your gut and you're experiencing a "die-off" or Jarisch-Herxheimer reaction. If so this should lessen over time, but maybe you are sensitive to this probiotic and you should try a different brand. See http://tinyurl.com/yalgcvpc