How to go platinum blonde from the darkest brown hair? Impossible?

Hairdressers did a test on my hair and used the strongest bleach, and it turned bright ginger, and brittle. My hair is now bleached once all over, and bright orange. It feels like hay! It has about 3 brown dyes over it and the ginger keeps coming through... But my hair is starting to fall out as it is so brittle. Is there really no way for me to go blonde?:/ I bleached parts of it twice, so its all uneven underneath and different kinds of ginger.. HELP :x