To be honest, it sounds like you want him to ‘accept’ his MS, to be able to talk about it and share experiences with others. Only without being frightened about what could happen in his future.
Those two things together may not be possible. Your partner appears to be in denial about the diagnosis. That’s quite common. It’s not such a bad thing early on. He perhaps doesn’t want to see the more disabled and/or feel disabled himself until and unless his MS progresses. Equally, you might not want to see the more disabled among us and fear for your shared future, just in case that future includes serious disability. That’s quite a reasonable perspective too.
Many partners of people newly diagnosed with MS, want their partner to open up, to discuss their disease. And yet people with MS have to be able to face up to the disease in their own time.
I suspect while lots of people find support groups and MS centres a great source of help, advice and fellow feeling, many people would prefer to stay well away. I’ve never been someone who wants to join local support groups. My former MS nurse used to run a women’s group, I went a couple of times but ultimately I hated it. It’s just not my kind of thing.
I get an enormous amount of fellow feeling and support from this forum. Again, it’s not everyone’s cup of tea, but we have to independently come to terms with our MS in our own way. We get support from family and friends, or from local groups, or from Internet fora, or indeed do without it altogether.
It’s great that you want to support your partner. But really, all you can do is find the sources of support available to him (and to you). Let him know they exist, let him know that you are there for him, and then allow him to choose what support he wants and needs, at a time that suits him.