Well, first I would say that dreams are not literal. Dreams are completely subjective, what a dream might mean to me might be completely different for you. It's what they represent for the one having the dream and although the action in th edream is huge, it could represent something small or vice versa.
I do not know how helpful this will be, but I checked a dream dictionary and it stated the following - "To dream that you commit suicide represents your desperate desire to escape from your waking life. You may be harboring feelings of guilt that you cannot get over and thus turning the aggression on yourself. Alternatively, the dream suggests that you are saying good-bye to one aspect of yourself and hello to a whole new you. It is symbolic of a personal transformation or a new stage in your life". Sometimes dreams are just dreams or a manifestation of our fears.
I would discuss it with your therapist. But if you are not having active suicidal thoughts, a dream doesn't have to mean anything. But I think you should still discuss it with your therapist. Just my opinion.
Wish you the best!!!