I'm sorry to hear about the difficult experiences you had with your dad when you were younger. It is not uncommon for past traumatic experiences to have lasting effects on a person, even after the circumstances have changed. The fear and anxiety you feel when your dad raises his voice may be a result of the emotional and psychological impact of the past verbal abuse and threats.
Experiencing such negative behavior during childhood can leave deep emotional scars and create associations between certain actions or tones of voice and feelings of fear and danger. These associations can be triggered even in situations where there is no actual threat present, such as when your dad raises his voice in a non-abusive manner.
It's important to recognize that trauma, especially from childhood experiences, can have a long-lasting impact on a person's emotional well-being and relationships. This is not something that can be easily overcome, and it is entirely normal to feel scared or anxious when confronted with reminders of past trauma.
If you find that these feelings of fear and anxiety are affecting your well-being or your relationship with your dad, consider seeking support from a mental health professional. A therapist can help you process and heal from past traumas, develop coping strategies for dealing with triggers, and work towards building healthier relationships.
Remember that healing from past trauma is a gradual process, and it's essential to be patient and compassionate with yourself along the way. Surround yourself with understanding and supportive people who can help you on your journey to healing and personal growth.