Dear Nugul,
First of all it wouldn't matter if this thread is deleted or not because ultimately we are not the controllers of other people's hearts...It's God who tests them and who gives them light or takes it away...your mere doubts will in reality have no consequence for anyone apart for the one he wishes to trial..which no one can stop.
Secondly, whether God exists cannot be determined by whether He answers your duas or not. God will be regardless of whether anyone gets their wish or not or whether someone disbelieves in Him or not.
As for why He doesn't answer your dua..I would say He has the right to do as He pleases. He is not obliged to answer you as He is not there to serve your wishes...still that shouldn't draw you away from being accepting him as your creator.
Also sister wearing the hijab has no reward or value attached to it if the faith has already departed from your heart..
I would suggest you approach the matter logically not just emotionally and to ask yourself what has happened to distance your heart from God..for example did you start to not agree with the will of God..is that where the conflict began?
Whatever it be I hope it enlightens your heart and bestows on it the due submission and faith.
I pray for you.