I am sorry to learn of your husband's recent injury, which your dream shows remains on your mind.
Roads in dreams are familiar metaphors for the "path we are on" in our lives. Because your dream sets you at a crossroads, we know you have an important decision to make. Will you choose to accept your new job? Your dream suggests your decision will affect your "life path" significantly.
In dreams, death is a metaphor for change and separation. In the context of your new job opportunity, your missing husband, and the murderer loose in your midst, both represent fears that your new job will separate you from him. Your husband's recent accident also is referenced in the dream. In real life, he recently cut off a finger. In your dream, his head was cut off. Because your husband's death in the dream is only symbolic (representing your fears of separation), his head soon becomes replaced with the head of your son's father, whom you know really is deceased.
Death in dreams should not be interpreted literally. Instead, your dream is representing fears that, if you accept this job, you may "lose" your husband -- as you lost your son's father many years ago. What is the meaning? This dream shows the strong value that you place upon keeping your family "all in one piece!" The value of this new job opportunity must be balanced with your commitment to your family.