Q:

What have I done here? 

I have a bad habit of lurking around and answering other riddles without offering my own.  So here is my first attempt the break the tradition, a simple rebus puzzle if you will.  It just might be too easy.  

Note: 

I had planned to post my puzzle towards the end of the year.  Also the riddle won't be accepted unless you can find them all. :) 

Hint 1:

 This puzzle is a hybrid one.  Both a rebus and some knowledge needed.  The theory is quite simple.  Just read in between the lines.  

A:

Is it perhaps 

 Linkin Park

Title:

 Linkin Park has a song named "What I've Done"

A:

It is-

 Linkin park, this was found by @sedrick first

Title:

 what i've done, a song by linkin park. 

Hidden clues:

 The wordings in the description may point towards some more LP song - Breaking the habit (OP used break the tradition and bad habit) Crawling (OP said lurking), In the end and Waiting for the end ,(OP said towards the end), The hint points towards the album - Hybrid theory, so remaining ones are probably from this album, I am guessing it is- My December, (reading in between the given line -toward the end of the year.)