Could you ask a friend or family member to be with you on that day? Someone to help keep you grounded and distracted?
Clearly your sense of Safety With Distance is being triggered. Perhaps you're feeling that is a boundary violation and worry he would be emboldened to return again at a later time? If the items are already boxed and are going to be set outside, is there a reason they can't be held at a more neutral location? Probably the court felt the items being set outside the garage would be enough. And even that is stressful for you. I like flourdust's suggestion. You need not be alone.
I'm assuming you've already changed the locks and security passwords?