What would I do in such a rut? I guess contemplate the awesomeness of God's love for me, rather than beat myself up.
Maybe I would fast from something for a specific amount of time (caffeine, ice cream, social media) to refocus my thoughts towards Christ and the cross.
Or I might begin a new Bible study in a group or online.
Or I might dedicate myself to a specific amount of time in meditation or silent contemplation per day (five minutes, ten minutes, twenty minutes?).
Maybe I would look for something inspiring and motivating to read, either free online or library or buy a book (I am lying I have no money to buy books or a library membership, I would find it online haha).
Find documentaries or music that motivate and inspire me to commit more to my spiritual path.