Ideally, you should never bleach your hair at home, as there is a high risk to end up with damaged hair and a questionable result. If for some reason, you cannot pay a visit to your hairstylist, then at least make sure to consult them. They should tell you to assess the current condition of your hair and decide if it is going to get through bleaching without negative consequences. If you are unsure, then it is better to wait until you can see a professional.