Going to give you my 2 cents, and I do not care what anyone has to say. Listen to my words my friend, please.
Mate you need to pray hard. Trust in God completely to guide you, and he will. Look, I'm a junkie, a drunk, a womanizer, an asshole, and i have a temper. I spent most of my life violently trying not to listen to God and he came to me anyway and I ran into his arms with weeping, horrible tears in pure humility. I now speak to him daily and pray, but as a Jew my tradition is different, yet still I have immense respect for both Islam and Christianity. My father is a Christian (my mother is Jewish and my parents had a jewish wedding, but my father converted to Christianity later) and my wife is a Sunni Muslim.
As a person struggling with hardcore depression myself and suicidal thoughts my whole life, and several suicide attempts, I know how low you can get. I said fuck off to God most of my life because as a large, muscular man (some say alpha male), I was not going to let some mythical tyrant dictate my life. Especially if I can't get on the piss, defend my honor, or shag a slavic girl hard, or have a shot of the morphine.
But I got it all wrong mate. God is not there to moralize and judge you and turn you into some sort of happy go lucky virginal cunt without a sense of individuality or free will. you don't have to up and change all your pleasures either.
God can show you the path within yourself if you choose to follow his light. I personally believe that Catholicism and Eastern Orthodoxy are healthier places to put ones faith than protestant churches, but the point here is that something stopped you. maybe for the wrong reason, but here's my advice.
You are in profound spiritual agony, which is obvious. I myself tried to switch the off switch before several times in very messy ways.
Let me ask you this. If you are so close to killing yourself - why not put aside your pride for a bit and try praying or try going back to church? or even something else.
You're worried about something for the absolute wrong reason man. Hell or heaven existing or not existing is no reason to believe in God or Christ. In my religion we do not even have a hell. so if there is no heaven, no hell, why believe?
No one is forcing you, and I do not believe in preaching. But something inside of you stopped you and that may be God trying to making you think of something deeper. You should pursue some form of spirituality in something. Buddhism, Christianity, Judaism, Islam, hell even paganism. The point is that something is deeper than the mere flesh and you sense it. Other people will argue against this with all sorts of logical arguments and all sorts of "reasons" why you should or shouldn't do something, but I think you should try opening up your soul and searching and asking for guidance. maybe you won't get any and maybe you won't become a believer again but maybe you will and it will help guide you. I did 14 years of atheism, and had a life changing experience and found my way back to my people's land in Israel. I found my way. I just trusted in God to help guide me.
sorry if I come off like a preaching arsehole here, and i do not mean to. I just hope you can find your way back to faith and that it can help you in tough spots. The pain of a woman hurting you shall pass, but deeper than that you need to find what can sustain you outside of her.
It's not about being perfect either or changing every aspect of your personality. fight against the pain by searching for something deeper within yourself.