Post Malone let down his guard and got vulnerable during his recent appearance on CBS Sunday Morning. In the Sunday, August 11, installment of the series, the singer reflected on the private hardships he endured before he met his partner, who helped him turn things around. “Four years ago I was on a rough path,” the Grammy nominee, 29, recalled, noting he was having trouble with “everything.” The star said those days were “terrible,” as even though he had achieved mainstream success, he was dealing with “loneliness.” The Syracuse, NY, native masked his emotions every day by “getting up, having…