You may want to try pre-composing your text layer.
Select your text layer and goto layer menu. Select pre-compose.
be sure to remove the effect that is causing the problem first.
Selecting move all attributes will keep all keyframable actions with the original file.
This will create a new composition that is the same size as the original composition.
and the original text layer is now a composition.
Now all effects will be bounded by the edges of the composition not the text itself.