I'd guess you had (according to Freud) a perfectly normal variation of the Oedipus dream where the guy who killed your step-dad was your real father and then you help your mom kill your dad so you and she can have each other all for yourselves. Dreaming this stuff is common according to Freud during sexual maturation. It isn't anything to worry about.
Knives and guns usually portend an upcoming verbal fight and arguement. The break in probably means that someone is going to butt into your business. The black man is usually an ill, bad, omen. That he changed to white means that you'll have some control, if not fore warning, of the upcoming event. Your being able to deflect the bullets means that for awhile you'll be able to 'carry your own,' but the relentless attack will take their toll on you. The mother/grandmother figure is probably a woman (for example at work or school) that you trust and look up to. So it could be that you'll get into a messy fight at work or school and it'll have to go to Humar Resources or the Principal or Dean. It's more a warning to be aware of not making enemies.
