Hi, I'd like to help you with your question.
It sounds like you and your husband might benefit from marital therapy. From what you said, you seem like you feel betrayed by your husband not backing you in your run in with the man next door. That is understandable. Although your husband may have had his reasons for his behavior, you both need to work this out in therapy so you both can understand how the other feels and this does not happen again.
Since you are still seeing this man next door, you most likely still feel very vulnerable. Who wants to be bullied then see the bully everyday from then on? What you can do to help yourself is run through all possible scenarios you feel this man next door could do. Then come up with ways you can deal with anything he might do. For example, he starts to threaten you. Think of your options in case he does threaten you in reality. What could you do? If it's contact the police, then play it out in your scenario. Then in reality, make sure you have your local police department's phone number on your cell phone and on speed dial on your home phone.
You can also talk with local law enforcement about your options should this man act out again. They can help direct you to the best ways to handle any situation.
Also, talk with your husband about the next time this may happen. See if you both can work out a way you feel protected and for you both to respond to this man.
I hope this has helped you,