I am

 Broken and mended broken and mended
Shattered and glued shattered and guled
My heart dont look like a heart any more

I am a broken piece of glass, if you touch me you'll get cut.

pushed down lifted pushed down lifted
scraped kissed better scraped kissed better
My hands and knees don't look like hands and knees any more

I am a wouned snake, taunt me and I may yet strike again

rejected taken rejected taken
ripped and sewed ripped and sewed
my love dosn't look like love any more

I am a bleeding wound, reopen me and I will infect you