When bleaching your hair you will usually need to bleach the hair twice to get the desired results from bleaching your hair.
But you cannot and should not bleach your hair twice in a row to keep from damaging your hair and keep the hair healthy.
So only bleach your hair once in a day and then wait another day or two before bleaching your hair again to prevent damage to your hair.
After you bleach it twice in a week then wait a few more weeks before bleaching your hair again if you decide to bleach the hair again.
What I would do is bleach the hair once and then wait a few weeks before bleaching it again especially if you already have damaged hair.