Dreaming about traumatic events!!!

So my mom passed away of lung cancer a year and a half ago and it was very traumatizing to me as I was only 19 at the time. She was the first close person I've ever really lost. So I didn't know how to take it. I kind of shut down the last week of her life and hid my emotions. I couldn't even go up to her casket at her funeral. I broke down. Couldn't even sit in the front row. I feel terrible because I was too weak to make myself go up to her. But I had already said my goodbyes the night before she passed. Anyways, last night I dreamt about her death and every detail was spot on and my feelings in the dream felt real. Usually when I dream of her, she's healthy and alive. Why am I dreaming of her death again? Is it my subconscious trying to tell me something or is she trying to communicate with me?