My cactus is cracked. Who can tell me what's wrong?

Your cactus is too dry. You water it once a month. But you can now apply soot to the cracks, then leave it for another 2 to 3 days, and then put it in the soil. It's best to change the basin, put coarse sand (pebbles are also acceptable) at the bottom, put some fine sand (not too fine) on it, and then pour enough water for a week (not on the ball). Then water it once a month. Cactus remember to bask in the sun!