Gwyneth Paltrow is Self's April cover girl, and the 40-year-old actress gives a revealing interview explaining how she fought a stress-induced panic attack by changing what she eats, which also ended up changing her marriage to Chris Martin. However, the mom of two also believes it's important to relax and indulge in some martinis with girlfriends Beyoncé and Cameron Diaz. We also cover Bradley Cooper's new model girlfriend, Suki Waterhouse, who is 18 years younger than the actor; Katie Holmes's plans for expanding her family; and Robert Pattinson's latest wrapped movie.