Please call. I hope that more men in this situation are calling. They won't judge you. First of all- call for yourself and then also... Call for your son, because you are his primary role model for how to be a man and you don't want to normalize seeing you be abused. You'd want him to also know it's OK for men to reach out for help and support too.
You're an adult, you have had years to mature but your child is so young, he doesn't know what is normal and what is not. He's senses a lot but not nearly with the ability of an adult.
Also, what is considered as "legally actionable" misbehavior for him to witness or experience is at a different level from what is considered actionable for you. You would need local input to determine precisely how behaviors and actions are viewed in your area.