thats a load off my mind

If someone says thats a load off my mind they mean to say that this something is much more relaxing and they can now be less stressed or frustrated about something. It is a cliche used when speaking about something that has been bothering them for quite a while and causing them undue stress, such as bills to pay or a big project to finish, and once it has been resolved, they will say it is a load off their mind.