YOU SAID:

My dad married my mom and then adopted a faliure (me)

INTO JAPANESE

お父さんはお母さんと結婚し、その後、私を養子縁組しました

BACK INTO ENGLISH

Dad married his mother and then adopted me

INTO JAPANESE

お父さんは母親と結婚し、それから私を養子にした

BACK INTO ENGLISH

Dad married his mother and then adopted me