Love can go a long way in my opinion. I would say to help him to realize that acknowledging that he may have sz in no way diminishes who he is or will have an affect on how you feel about him.
With my son it seems to help that we don’t discuss sz much. We discuss anxiety and about 6 months ago, I don’t remember exactly when, I started talking about regulating neurotransmitters like dopamine and seratonin rather then trying to ‘fix’ him. He doesn’t need fixing. Just last night he was discussing/asking which neurotransmitter his Gabapentin/Neurontin affects as we can’t figure out why he is getting an affect from a anti-convulsion med but he is.
Ask him if you can attend one of his therapist meetings with him. Do your best to let him know that you are acting or speaking from a space of love. I find when I ask my son if I can speak/talk to his workers I get a better response.