be a weight off your shoulders
if something is a weight off your shoulders, you are happy that you do not have to worry about it or feel responsible for it any more If you could take over the job of organizing the party, that would be a tremendous weight off my shoulders.
be a load/weight off your mind
if something is a weight off your mind, you have been worrying about it and you are pleased that the problem has now been solved I'm so relieved I don't have to give a speech - it's a real load off my mind.
