HELP! blonde hair disaster?

Okay soo ive dyed my hair from red to blonde... I've just put a toner on it as it was a pale yellow colour and my hairs turned blonde with silver highlights. My hairs in really bad condition atm. I've found a dye which matches my hair extensions and i was wondering if it would be okay to put a permanant dye on it.. The last time i dyed it was on monday.. its not saturday. my hair is reallly dry and brittle atm