dream: ex boyfriend tried to kill me

I had a dream that an ex boyfriend tried to kill me. The weapon was interesting itwas strange like a dagger but also like a letter opener. like a heart shape at one end for the hilt and a tear drop at the other for the point. he stabbed me in the chest in the centre but there was no bone, blood was everywhere it wouldnt stop flowing but i would not die. my friends were trying to help and get me to a hospital, but we kept on getting stopped he my ex kept on following us, still with this weapon,
this dream is concerning me please can you shed some light on what it means
i went out with him for 3 weeks and i got a mate to dump him