Maybe it's a fear that you have. Shows how much you love him.
I'm no expert, but it sounds like fear and missing him. I've also found that things that happen during the day can affect your dreams. For me, they always seem to mash together like a poorly put together play.
I don't believe it's anything to worry about! :) I hope you get the chance to see your son <3
To dream about the death of a loved one suggests that you are lacking a certain aspect or quality that the loved one embodies. Ask yourself what makes this person special or what you like about them. It is that very quality that you are lacking in your own relationship or circumstances. Alternatively, the dream indicates that whatever that person represents has no part in your own life anymore.�In particular, to dream about the death of your living parents indicates that you are undergoing a significant change in your waking life. Your relationship with your parents has evolved into a new realm.�If you dream about the death of a child, then it implies that you need to let go of your immaturity and start being more serious. As your child reaches certain milestones and grows into an adult, dreaming of their death may be symbolic of their own self-discovery, transition and transformation into a new stage of life
You love your son, and you are experiencing natural paternal anxiety and fear for his safety and well-being. I'm not a therapist, but you should probably be talking to one, and maybe find a support group.
you care for your son, you worry fir him. Which is good,