I am very sorry to hear about this but all things happen for a reason.
We have three aspects in our lives and they all need care and growth, the mental, physical, and spiritual. The growth in these three aspects gives us balance and strength for living (and throughout our lives). This is a great opportunity for you, and your husband to 1.- get closer to your child and see what kind of TV, movies, reading material is getting into his little and sensitive head, and protect him taking the right measures. 2.- developing his spiritual life; I am sure you both have some kind of religion, and if not, is time to get it. We cannot give to our children what we do not have. 3.- keep an eye also if the child got these fears from friends or others.
Do take care of this. His mind is absolutely very important, and how you treat it. You are very important to your child in order to grow healthy. If you need help for this, get it. Just make sure is good and proper for his age....and lots of love and reassurance that you both love him. He needs to know that the most probable thing is that you are going to see him grow, and even get to see his own children, that God gave him to you because of that, otherwise he would have not been born.
I went through the same with one of my sons but a bit worse 'cause I a single mother and he hated me for quite a while and cried a lot, but things got worked out and now I am 64 years old, he is over 30, and I got no know his first child, just like I told him it would be. Now he laughs happily.
Last advice...a lot less TV programs, and a lot more family life, especially with you the mother. We mothers are very important; we give life in more than one way.(may God bless you and guide you). L..