Hi edthenapper, and welcome! I understand your confusion and yes, it's tempting to create a full itinerary to cover all of your plans. But please don't, if you want to enjoy the fresh mountain air and don't like spending all your time in trains. It's much better to pick two or three regions at the most and look for nice, scenic transfers between your resorts. That means that you have to make choices and that you won't be able to do all the things you and your girlfriend have in mind. But this is reassuring: whatever you pick, it will be beautiful (if weather is fine or course) and I'm pretty sure you won't regret any of the choices you make.
Well, an itinerary could look like this:
- 2 nights in Lausane;
- travel onto Zermatt and spend 2 nights/approximately 3 days there. That's not too much, as there are many things to explore and the views are amazing;
- travel onto the Bernese Oberland, either via the scenic Lötschberg Regio Express or with a detour covering part of the Glacier Express. You could travel to Andermatt by Glacier Express, for example, and then switch trains heading for Interlaken via Göschenen and Lucerne. This requires a full travel day, but it allows you to discover part of the country and experience a wonderful train journey;
- spend the rest of your time in or around Interlaken and visit the Jungfraujoch, make a boat trip over one of the lakes, and so on. You also may also like a day excursion to Lucerne, but the Bernese Oberland itself offers more than enough viewing points as well;
- get back to Geneva over the Golden Pass route via Zweisimmen and Gstaad.
In this case, you should skip St. Moritz and the Bernina Express. It can be fitted in in this itinerary, by making the full Glacier Express journey to St. Moritz and making the Bernina Express trip from there, but that means you'll be spending more time om (train) traveling.
This is just an example of course. There are lots of variants. Did you discover the timetable
? It will show you exact traveling times, allowing you to estimate whether train journeys are too long for you.