About God and yourself and you being and ex-muslim and the effect it have at yourself and the effect it could have with your relationship with your parent in my opinion ; You need to ask yourself whether God fail you or you fail yourself,I cannot speak for God but on human nature maybe because i am myself a human being so i will give you my take on it . If you dont want to study engineering then dont force yourself on it if you gonna be miserable with it and cannot bare the burden of your choice being strip from you either willingly or not because some people can bare that kind of burden sacrifing their own choice and happiness for other . So just tell your parent your are literally dying from the course and cannot see a future in it for yourself . Tell them even if they force you to finish the study you yourself maybe will never work in the field your are studying in,more or less a dead end . But i caution you to consider it carefully on what is it you want with your life and the factor that can help you attain it,what will be the overall percentage or the likelihood of you getting it or you just can take a "gamble" for you future by then whatever the result will be you will have to live with it .