Is it permissible for me to call my husband "my soul" or to tell him "I cannot live without you" as an expression of my love and care for him?

For a wife to call her husband "my soul" (roohi) or "I cannot live without you" is not problematic. It falls under the category of good companionship. By this, the woman intends to express the husband's high status and her love for him, not the literal meaning of the words. This is similar to common Arabic expressions like "May my father and mother be sacrificed for you" (fidaaka abee wa ummee). These phrases do not carry the meaning of actual sacrifice, but rather are expressions of love and appreciation, as stated by An-Nawawi.