Tell Me... Where Did I go Wrong?

There are nightsWhen I can't help but cryAnd I wonder why you had to leave meWhy did it have to end so soon?:When you said thatYou would never leave meTell meWhere did I go wrong ?What did I doTo make you change your mind completely ?When I thoughtThis love would never endBut if this love's not ours to haveI'll let it go with your goodbye