You have lost your heart. Either you removed it via The Heart of Darkness (see V20, p. 210), or an elder did it to you, but either way you no longer have easy access to it. The heart might be in the possession of a foe, or simply missing. If it turns out that a Cainite possesses the heart (say a Setite elder, or your sire) you must obey their every command. If it’s merely missing, the anxiety and obsession to find it interferes with your nightly existence, and may increase the difficulty of Willpower rolls by +1 at Storyteller discretion.