over and done with

Over and done with means to do something difficult or unpleasant as soon as you get the chance so that you dont have to worry about it later on. This is usually in reference to something being very unpleasant and just the thought of it causes stress or worry. By doing this thing right away, whether it is a job, school project, or chore, you can have it out of the way and know that it is done and no longer have to worry about it.