color over color 3 days apart

went to the hair dresser saturday, the highlighting over the summer, had gotten my hair way to light so i asked her to go over it and pull it all through. the salon was busy and she was doing a partial high;ight on another client while i sat with dye in my hair so maybe she left it on to long but when she rinsed it out my hair was red...pomagranet red. i was horrified. she didn't have time to fix it said i will have to go back tuesday. i walked into my house and my kids were rolling on the floor, it almost looked purple. i washed it a couple dozen times, now they say i just look like ozzy osborn :(
my question is, i have such thinning hair already even though i'm only 40, (must be hereditary) but if i have her recolor it, will my hair fall out or will my hair be damaged, would i be better off having it highlighted to lighten it...any thoughts would be appreciated....