Why does this switch trip the breaker?
Not all white wires are "neutrals", and not all "neutrals" are white.  Some white wires are in fact used as "hots", especially those that are marked with black tape/marker/paint, and/or connected to single pole snap switches.

You should put everything back the way you found it, and contact a local licensed Electrician. Better yet, just shut off the breaker and call the Electrician. You can explain to them what you did.

This advice may sound harsh, but it sounds like you don't know much about electrical wiring.  If you'd like to learn, take a course at the local college, or read some books.  Messing with wires in your home, is not the way to learn the basics.