What is the expression/slang to describe that you suddenly decided to go [travel, change environment]?

Bail could work,

to give up on or abandon something, as to evade a responsibility: His partner bailed out before the business failed.

and

To leave; cut out, split: Bruce has bailed from the scene entirely/ Most of my friends had bailed to stay with other relatives

Alternatively, split:

Slang. to leave; depart.

and

to part or separate, as through disagreement; sever relations:

and

a breach or rupture, as between persons, in a party or organization, etc.

The best word to describe the concept that you're outlining is "Wanderlust". The reason it has a captial "W" is that it is a loanword from German where all nouns start with a capital letter (like Weltschmerz or Schadenfreude).

You have (or are experiencing) Wanderlust.