Being pot committed occurs because you have not been playing with enough caution and is never a good thing. It can happen if you have brought too few chips to the table, a failed bluff, or just a run of losers. It can be a nerve racking experience because it means that you do or die on a single card. It is the poker equivalent of a dead end.
Don't over commitment
If you keep an eye on the size of the chips in relation to everyone else, you should be able to avoid the situations where you have to be pot committed. At some point of course, you will have to bet the majority of chips. But you want to avoid this situation as much as possible, because you can be running into too many situations where a single throw of the dice can blow your chances of staying alive.
Poker is about keeping safe and staying alive long enough to let your skill and decision making come through. Do not fall into the trap of making the wrong move and over committing otherwise your poker career will be very short lived.