Any way, you could check again with the agency or another one? You have to pursue what you love and especially you have a strong gift. You are young yet. The WT org will eat you alive, your spirit and soul. Be prepared to have to leave your mom to her choices. You obviously love her. But you must love yourself too.
I am a grandma now, have 5 grown children, all put themselves through college. I am glad they have freedom of their mind and heart and have fulfilling lives. Moms cannot ask for anything more.