Possibility of fiancé having Huntington’s

I don’t really know what I’m expecting to get out of this but I have so many emotions and I guess I just need a place to put them. There’s a lot to unpack here. I’ll start by saying my fiancés family has a history of HD on his dads side (allegedly). I did not find this out until he decided to tell me about a year into our relationship, we were doing long distance and he called me after having a few drinks and dropped an absolute bomb on me. I had never heard of the disease and he did not elaborate, just told me his dad has it & to “look it up” and then hung up. I probably cried for 3 days straight after doing my own research. The worst part is that after initially telling me this, he really has yet to talk with me about it which makes things worse. 3 years have passed since he decided to tell me, we just got engaged and have such a great relationship but this has been the elephant in the room ever since he’s made me aware. I love him so much and nothing he tells me could make me leave him. He doesn’t have a relationship with his dad whatsoever, so I am not exposed to the extremity of the disease first hand but I know he is at end of life in his late 50’s. His family including his dad has a history of drug/alcohol addiction so we really never see them and when we do it’s not like I am able to talk to any of them about this. Supposedly his aunt and uncle have HD as well and I have met them but they’re always drinking & were users in the past so it’s hard for me to separate the disease from the fallout of addiction. My fiancé has not been tested and is choosing not to as of right now and I support him, but we just got engaged and I want to have children and a family so badly. It’s hard because I refuse to bring a baby into this world knowing there’s a possibility that they could inherit the disease. Also, imagining my fiancés health declining makes me literally throw up. He’s so healthy, smart, sweet and caring and I can’t imagine him any other way. It’s so hard. These are thoughts that go through my head daily but I feel as if I can’t voice them to him. I break down about once every few months when he’s gone at work and just cry alone and go down the rabbit hole of researching what to expect even though it’s not even confirmed if he has it or not. He is only 26 so I know there’s time but I can’t help but think about the future especially now that we are engaged and one step closer to starting a family. I feel like I need a therapist or someone to talk to that actually understands what this feels like because although I’m not in his shoes I feel so strongly affected. Sorry for the trauma dump, just trying to find an outlet for when I’m feeling like this.