crying for 3 weeks straight

Hi there, I am new to this board and already feeling better about my situation after hearing that other women care about their hair as much as I do.  To make a very long story short - My regular hairdresser went on a 2 month vacation and I was in need of a root touch up on my highlights.  One of my best friends is a hairdresser but I never went to her because I didn't want to mix friendship with hair ( incase i didn't like the results)  Well she convinced me to come see her and said she would be very careful.  Bottom line - it didn't turn out okay - I was a blonde when I came in and left looking like Elvira. I have naturally light brown hair and have been highlighting it for 9 years. I wanted the roots touched up and some brown lowlights to break up the color, as well as the underneath to be brown as well.  Well she put foils in for the hightlights and colored everything else brown - she said it was a new technique.  (My other stylist just alternated foils - one blonde, one brown)  Anyway - she used a pre Darkener or filler in the spots that she did brown and the whole thing came out dark dark ashy brown.  The highlights didn't even show and what did come out was like white stipes that looked like gray against the almost black brown.

I came back 5 days later to get what I originally asked for and she put highlights over the dark brown and put a color rinse over the brown to make it less ashy.  This took 4 hours and came out a horible muddy color!  The blonde is just plain blah and it looks gray in some parts still! The worst part is that my friend kept saying that I wanted a "makeover" and that it wasn't her fault.

I am so upset and don't even know if I can continue my friendship with her.  I brought in pictures of my hair in the past and it didn't look anything like them.  She looked and them and said it did!  Such a lie!

Anyway, sorry for going on and on about this but I have one question - I am going back to my old hairdresser next week.  It will have been 4 weeks since my friend "fixed" her mistake and 5 weeks since the original mistake.  I am just wondering if 4 weeks is too early to get it a nicer shade of blonde?  My old hairdresser said she will just use a very low volume for about 10 mins or a toner to get the blonde a nicer color.  MY MAIN CONCERN IS THE HEALTH OF MY HAIR. It is breaking off in some sections (where the blonde is) and is very dry and hard to style. I can't wait any longer than 4 weeks, and have been conditioning it like crazy. 

So do you think it is safe to tone it/ low volume and is it breaking because of what my friend did?

THank you so much for any responses!  My boyfriend has no sympathy for me because my hair looks okay to the naked eye - I am mostly crying about the damage.