Do you have a T? Would it be possible to take him to an appointment and share it then, that way your T could help you get through that conversation, as well as curb the reaction you fear (and reasonably so)? While you will probably still get a negative reaction, hopefully that environment will help him express his concern in a more controlled and supportive way... Then maybe your T could help give you both advice/help you work on a plan on how you will continue to handle this situation (and any similar that may happen in the future) together...