A year ago, comedian Alva Sparkles didn't want to be alive. Now, she's celebrating her survival with a laugh-out-loud show focused on mental health. While a sense of triumph usually waits until the end of a performance, there’ll be a quiet, thrumming victory felt from the moment comedian Alva Sparkles takes the stage at Yuk Yuk’s on May 10. As host and MC of The Best Medicine—a show she created that’s giving all proceeds to the Mental Health Foundation of Nova Scotia—she opens the evening, yes…