I commend you for supporting your SO. I'm DID so I know how hard it can be but I also know how much it means to your SO that you are sticking by him. We need security.
There are some forums out there you can check out that are for friends/ family of DID. I don't know of any off-hand. I had sent them to my husband & mom but have since deleted them. It helped them understand where I was coming from & that they weren't alone in their frustration. I'm not saying you can't be here, just giving you an option to go to other places as well. The more support you & he can get, the better. I would recommend he go to therapy. We can't do this alone. They will help him so he won't be hosp. & lose his job.
I wish you & your SO the best.
Love,
RhysMadison