i'm afraid

• scaredFeeling fear or alarm
• nervousUneasy and apprehensive
• worriedTroubled by uncertainty
• anxiousTroubled by uncertainty
• fearfulFull of fright

terrified · dread · sorry · unfortunately · hesitant · trembling · uneasy · apprehensive · regret · apologetic · timid · frightened · sadly · shaky · reluctant · alarmed · spooked · cowardly