Fried hair disaster!

Okay ladies so back in March I decided that I wanted to go fully blonde, well I went to my local Walmart to smartstyle because I had went there before and a different girl had done, she done excellent this time it was someone different well in the process she completely fried my hair, I need tips and tricks to help it grow out fast because it is still barely growing😓 I’ve kept it trimmed and I’ve done leave in conditioner treatments. So leave some tips please!😊 anything will help!! Or recommendations on vitamins!