Jennifer Lopez is staying positive as she celebrates her 55th birthday amid the raging rumors of an impending divorce from her husband Ben Affleck, 51. The singer, who spent her big birthday in the Hamptons on Wednesday while Affleck was off on the opposite coast, is said to be looking for a “fresh start” as she enters a new chapter of life, RadarOnline.com can reveal. A source said Lopez “is doing her best to stay positive and focus on the great things in her life” and “always loves getting to spend time on the East Coast, especially during the summer”. “It’s been nice for her to be surrounde…