Keith Cullen has endured a difficult path, one filled with setbacks, disease, and heartbreak, but he’s finally ready to become the queer pop sensation he’s always known himself to be.The Dublin-born Cullen, 36, started out in a less-than-musical fashion; at just 18, Cullen founded an Ireland-based marketing firm, and for nearly a decade, he built the company up from nothing and became a verified success story. “But,” Cullen tells Billboard, “I wasn’t being true to who I was.