On-line I like to relax playing mainly freerolls, it really does not matter to me if I win or lose, because what have I lost, Nothing!
If I win however it is a great feeling because all Free money is a bonus,
When I played in Live games I have a similar approach to the game, the buy-in is just the ticket price for entering the ride and how long the roller coaster last's is down to how well I play.
If losing the buy-in is a problem to you, then I would suggest you play for lower stakes or change the Game altogether, playing as if your life depends on winning or losing puts too much pressure on you mentally, and game choice could be anything from cash games to full MTTs.
Find the level you are comfortable playing and stick to it, there is nothing worse than playing with frightened money.