What you described is handling a possible tilt

However you have to realize that poker is a game of odds and those are usually not a 100% in your favor.

Your method of leaving the table is fine as long as you play online ring games, but if you ever plan to play live games or Sngs/tourneys online it will not be as effective.

If you decide poker is a game you want to play you have to learn to accept the fact that sometimes people will catch their runner-runner or their miracle river card and this is just part of the cost of doing business in this game.