What you can do instead, so you can feel confident, is:

1.  Try to figure out the basics of what you are concerned about as best you can.

2.  Figure out what could come up based on what you understand about this thing.

3. Plan the best way that you can help things go as well as possible.

When trying to do well in the different areas of your life, one point that can help you is to set goals that are based on what you would like to ideally accomplish.  If your goals are not to do something, it can be discouraging to focus on what you don’t want to do.  Whereas, if you focus on the best that can be done, then you can keep improving and moving forward, instead of being limited by a lower goal.