What are the after effects of seeing someone close to you die infront of your eyes? my mother?

my mom ped away away a few mths ago.She had a heart attack & I was holding her up when it happend.It was very traumatic for me.(I was very close to her)I do have physical effects like chest pain.Emotionally its awful also.But I wanted to know what are the physical & emotional effects to a just turned 20 yr old girl.Bec im young & just got out of being a teenager how will it effect me? I would really appreciate your help.thankyou