Your dream sounds quite intense and may carry several layers of meaning. Seeing an older woman dressed in black could symbolize wisdom, guidance, or a connection to the past. The black dress and veil often represent mourning or loss, which might suggest you are processing feelings related to grief or change in your life.
The feelings of immobility and the vividness of the experience suggest that you might have encountered a state of sleep paralysis, which can often be accompanied by visual or auditory hallucinations. This state can evoke strong emotions, and your heart pounding and ears ringing are common physical responses to such an experience.
Yelling "Hello" and the woman's subsequent fading might indicate a desire for communication or connection, perhaps with something or someone in your past. This could also symbolize a wish to confront or acknowledge feelings that you've been avoiding.
Overall, this dream could be a reflection of your subconscious processing emotions related to loss, change, or a need for closure. It might be helpful to reflect on any recent events or feelings in your life that could relate to these themes. If the experience was unsettling, consider grounding techniques or discussing it with someone you trust to help integrate the emotions it stirred up.