I'm not sure how to make a vow of abstinence, could anyone help me?

its ok to make an abstinence vow if あなた are not one. abstinence is not only link to Christianity.
to make a vow, find someone who あなた would trust, a childhood フレンズ who あなた are close with would be ideal. あなた could ask your parents but i would suggest not. it hard to explain why but its just better if its a close friends. when あなた make your vow, whatever relationship あなた are in, u are oblige to tell that person. whatever あなた do in that relationship あなた have to tell that person not in specific detail but in brief. so the person can be accountable for whatever actions and アドバイス you.