When I'm struggling with a project, I try to write something new. Sometimes I change the setting of the scene or the POV of the character. Sometimes I put that work aside and try writing in a new genre, in a different tense, or for a different target reader.
Reading helps fill my "well" of creativity, so I have more to draw from. Exercise helps with that, too, especially if I can get outside and spend time in the sun. When I feel like my well is restored I will tackle my project again and hope for a better result.