The key card is present but its support is thin.
Prioritize useful support such as Wary Watchdog or Spineseeker Centipede.
Use Broodspinner or Wary Watchdog to surveil, then cast Under the Skin to manifest dread and recover a useful permanent, including the card just milled. Maintain four types for Drag to the Roots.
Your deck enables the plan but is losing the early turns.
Take a castable early creature or efficient answer before another expensive payoff.
Returning the only card of a type can turn delirium off. Count the remaining graveyard types before recursion, and do not expect Say Its Name's three-copy bonus without all three actual copies.
The support is missing
Favor independently useful creatures and interaction if the narrow support does not arrive.