You and your husband need to learn forms of healthy, positive discipline. You also need to understand what behavior is appropriate for your son's current stage of development. When you learn more positive ways to discipline and understand why your child behaves as he does, you will parent better and give your child the compassionate support and guidance that he needs.
I believe in the saying, "When we know better, we do better." Please ask your pediatrician to recommend some parenting classes for you. Your HMO, local adult education program, YMCA, or children's advocacy organizations might also provide parenting classes. I'd also like you and your husband to read, Positive Discipline: The First Three Years by Nelsen, Erwin, and Duffy. Soon you and your husband will be able to discipline with love and understanding, instead of spanking out of frustration. Get the knowledge you need and watch things get better. Thanks for writing.