Worrying before any bad thing happens is a pretty useless and damaging habit. Its like inflicting trauma multiple time which might even not happen.
A research shows 85% of things what we worry about, never even happen. And I am really sure that what 15% even happen is much less in intensity what one is perceiving. In other word most of the time people worry about the worst case scenario and loses the focus from the goal and misses the opportunities ahead.
I recommend you to stop worrying and start working out the plans to avoid the situation you worry about.