One strong story you have here. With shamanic viewpoint, story could be explained like this:
During your argument a sensitive part of yourself get seriously hurt. It might been fragile, soft spot in you, you were never aware of. That part of you wanted desperately run away from situation, not to get hurt more. That may be one possibility, why you felt broke. (Or nothing got broke, but somethng get triggered.)
At the dream that part of you came back as a form of dog, begging to kill himself as you did. So, you killed a part of youself, which most probably was at it's end of time, not needed any more or whatever the reason. (Or the dog have nothing to do with you personality, and it is something entirely different matter) But death is not the final end but time for transformation.
Bees are also connected to element of death by myths and by their nature to transformation. All insects go through several phases from egg to adulthood. I guess bees are also the most valued insect on this planet. It was nice to have them there, just to mark it out, you had some real staff going on. It is not creepy, it is reality, when it happens.
Also, when something real come to across, it will not explain itself, but leave people a bit wondering, what it means. With that amount of suffering, your story sounds quite much like shamanic initiation with dying and everything, but main spirit is missing. Instead of animalspirit killing and claming a person, it was you killing a spirit in animal form.
That is most interesting and not usually heard of. You have experinced something very unique. To the question "Why?", if I were you, I would try some form of vision quest ot find answer. It is not needed always to do the hard way. For me it was enough just to find comfortable, wide, open place a bit higher at dawn and sitting there until I felt I was done with my question. Have the question in mind, then drop it and wait the aswer. No eating, drinking any other action, but wait eyes open.
That's what I suggest to do to find out more, and I'll be curious to hear, if something come up.