Snoopy and Cherie are right. The first year or so can be tough because one, you are new and notice everything. Two, many symptoms are just that, symptoms. The way doctors try to gauge your level of ms is how you progress. Many times they wont even say 100% because ms is so unpredictable that they wait five years or so to see how things go.
The added stress of a new diagnosis adds to that. Stress is not a friend of ms and can sometimes exacerbate your symptoms. As far as vacation goes, just take it easy. Hubby and I always rest one day for every day out. Sometimes that doesn't work but I think you understand what I mean. If you go out and have a filled up day, the next you have a more relaxed day. We raised two children around hubby's ms and they understood and adjusted just fine. We did not let ms take over but adjusted with it.
I say don't let this rule your fun. Maybe the vacation is just what you need.