When the original “Star Trek” TV series was canceled after three seasons in 1969, William Shatner was newly divorced, saddled with alimony and child support payments and “totally broke.” He took jobs performing in summer stock and lived in his pickup truck with only his dog for companionship. “My life got desperate,” he admits in his latest memoir, “Boldly Go,” out next month. Though he’s since enjoyed plenty of work on the big and small screens, he observes that the “feeling in your gut of not knowing where your next meal was coming from, sadly, on some level, never really goes away.”