Sorry to hear about this, Wills. My husband was diagnosed with cerebellar ataxia when he was 60, the slurred speech being one of the signs. We always used to say it was like motor neurone disease, as that's what people know about.
As you say, you just get on with it, as there's nothing you or the doctors can do except monitor it. Speech therapy helps a bit, as it teaches you not to panic.
We were told that most people who have it die of something else as it can be very slow to progress. If it's affecting your handwriting, make sure your new husband has power of attorney for financial affairs. The diagnosis was a relief to him as at least he knew there was a reason for his symptoms.
Do what you want to do now, don't put things off.