These are just some things to do in Switzerland
You should think about going to the Cailler factory. It is really fun and you get to learn a lot about chocolate! You also get to taste lots of chocolate for free! And buy some!
You're in Switzerland! Shouldn't you build a snow fort or have a snowball fight?
You should go geocaching. It is lots of fun! I you don't know what it is here's a link: Geocaching 101
If you can afford it going skiing would be awesome! But beware of altitude sickness.
If you can't afford skiing you could still go on a cable car or gondola ride. Maybe up to the viewpoint on Klein Matterhorn?
Maybe try ice skating. There is a rink in Zermatt, and you can rent skates in some sports stores.