Maybe you can do something like this:

var theStringFromDB;
var theNumberOfCharactersThatsFitsInTheLabelOnOneRow : String;
var theNumberOfCharactersThatsFitsInTheLabelOnOneRowOnRowTwo : String; 
var theLengthOfTheStringFromTheDB = theStringFromDB.Length;
var newRow;
var newRow2;

if (theLengthOfTheStringFromTheDB >= theNumberOfCharactersThatsFitsInTheLabelOnOneRow)
{
newRow = theStringFromDB.Insert(theNumberOfCharactersThatsFitsInTheLabelOnOneRow, "/n")
theStringToDisplay = newRow;

if (newRow.IndexOf("/n") >= theNumberOfCharactersThatsFitsInTheLabelOnOneRow)
{
newRow2 = newRow.Insert(theNumberOfCharactersThatsFitsInTheLabelOnOneRowOnRowTwo, "/n")
theStringToDisplay = newRow2;
}
}

Haven't tested and verified at all, but it might get you an idea.

If the GUIStyle that you use to display your label has wordWrap set, it should wrap when necessary.