Trauma happens when our survival response meets its threshold. Post traumatic reactions happen when our survival response meets non-survival situations.

You intend to respond as your best self at work, with family, on your commute, and so forth. Sometimes you don't even notice the threat, or whatever causes that flooded feeling. 

You respond bigger than you wanted to. Or, 

You pull back, way back. Or,

You go flat and numb. Or,

You just try to please the person who seems like a threat. 

You feel powerless, or too powerful. You've talked with friends, family, your doctor, a therapist. Sometimes you go a while without those reactions. But you want more consistency. Predictability. Peace. 

Developing a sense of safety is the first step. Next you need to get in deeper touch with your body and its feelings. And you want to process, to get in better connection to your past. 

It might be time for trauma therapy to support you being the person you know you are inside.