Breaking Up Is Hard To Do -- Neil Sedaka

Don't take your love away from me Don't you leave my heart in misery
If you go then I'll be blue 'Cause breaking up his hard to do

Remember when you held me tight And you kissed me all through the night
Think of all that we've been through Breaking Up Is Hard To Do

They say that breaking up is hard to do Now I know, I know that it's true
Don't say that this is the end Instead of breaking up I wish that we were
making up again

I beg of you, don't say goodbye  Can't we give our love another try
Come on baby, let's start a new 'Cause breaking up is hard to do

hit number one on the Billboard Hot 100 on August 11, 1962 and was a solid hit all over the world, sometimes with the text translated into foreign languages. For example, the Italian version was called "Tu non lo sai" ("You Don't Know") and was recorded by Sedaka himself.  (wikipedia)