Bleach hair---severe breakage

Hi,I have been having my very dark hair professionally bleached for years.My hairdressers have always been very careful not to overlap.The guy that had been doing my hair for the past year has gotten very careless lately and letting it overlap,he just seemed to not care that my bangs were breaking off to about 1 inch! I was mortified that he laughed it off.Today I went to another lady who was kind and sympathetic to my breakage.She took extreme pain to be very careful.She used Matrix bleach and put conditioner on my ends throughout the entire process,she had me under the dryer about 50 minutes!It looked great at the salon,the bangs did not have the usual fried look they have been having.But in the car driving home,I ran my fingers through my hair and gobs of hair kept coming off.By the time I was home I had a lap full of hair and a face full of tears.I closely examined the hair that was coming out,it is the longest hair from my scalp,it lookes like it is coming out from the roots,about an inch of it looks "melted or withered".I am just a mess with worry right now.Am I going bald?Did she leave it on to long?I honestly don't think she overlapped so why is hair melting off at roots?I have been on Mediafast diet the past month,lost 16 lbs on less than 1,000 calories per day,was the new growth weak hair from the diet that the bleach just finished off?Please help me,I feel my life is over! What products will help me?