Peter Debruge Chief Film Critic We’ve all heard Celine Dion’s “My Heart Will Go On,” but if you really listen to the lyrics — “Love can touch us one time, And last for a lifetime … Near, far, wherever you are / I believe that the heart does go on” — the tragedy they describe applies to more than just comely Rose learning to live without her blue-eyed cabin boy. Eighteen years after “Titanic” made her a mega-star, Dion lost her husband and manager, René Angélil, and the singer has made no secret of her struggle to move on since. An old-school, straight-faced studio romance featuring five new songs from Ms. Dion, writer-director Jim Strouse’s “Love Again” is all about such healing — to the extent that if it were a book instead of a movie, it would be filed in the self-help section. Liberally adapted from the 2016 German film “Texts for You” (“SMS für Dich”), the more-creepy-than-cute plot focuses on a grieving New York children’s book illustrator who sparks up a new relationship with the complete stranger who’s inherited her dead boyfriend’s phone number. “Truly, Madly, Deeply” this isn’t.