matey I used to work in a hairdresser for a while...I can honestly say that if you bleach it again so soon your hair WILL fall out.
basically what happened is that permanant hair dye coats the hair and works at opening up the hair follicles to insert the colour.. You did this twice right? so your hair will be pretty damaged to start with.. then within two weeks you tryed to strip that hair colour, (which is why it didint work because the colour is permamant) and that would have made your hair very weak... bleach can turn your hair to jelly..and then it will fall out....
It is THAT important to have pink hair? Cause I would seriously suggest NOT to bleach your hair again...not for a couple of months at least...
plus put a whole lot of conditoning treatment into your hair to try to smooth the follicles and get your hair back into a better condition...

hope this helps.