What Bahá'u'lláh meant primarily with "sciences that begin and end in words" are those theological treatises and commentaries that encumber the human mind rather than help it to attain the truth. The students would devote their life to their study but still attain no where. Bahá'u'lláh surely never meant to include story writing under such a category; and shorthand and typewriting are both most useful talents very necessary in our present social and economic life.
What you could do, and should do, is to use your stories to become a source of inspiration and guidance for those who read them. With such a means at your disposal you can spread the spirit and teachings of the Cause; you can show the evils that exist in society, as well as the way they can be remedied. If you possess a real talent in writing you should consider it as given by God and exert your efforts to use it for the betterment of society. [This advice was given to a believer who asked whether such skills as shorthand and typing, and the writing of stories dealing with human experience, would be classified among those sciences that "begin and end in words", as mentioned by Bahá'u'lláh.] (From a letter written on behalf of Shoghi Effendi; The Compilation of Compilations, Vol. II, Writers and Writing)