"After getting closer, I feel like saying that this has been heaven"

It's only been three months, and he's threatened or tried to kill himself three times. Even you said that he acts distant and "hateful." That's not heaven! Please, NEVER feel like you "caused" him to do these things to himself. It's HIS choice, always. None of this is or was your fault. You're allowed to keep things to yourself if you don't want to discuss them with him, and it's inherently inappropriate for him to force or pressure you for hours so he can get his answers. If you don't want to talk about something, reserve the right to say "I'm not going to talk about that with you." If he pressures you, leave.

Let him know that he can't control you like this, and feel free to make it as direct as possible. He does these things to force a reaction out of you. It's terrible, it really is. On one side of the coin, if he threatens to hurt himself over your response to a conversation topic and you leave the room/house/etc, it's possible that he'll continue to hurt himself. On the other side of the coin, if he threatens to hurt himself over your response to a conversation topic and you leave, he learns that he can't hurt himself to get your attention anymore, and has no choice but to establish healthy methods of getting your attention. It's hard to take the 'tough love' route of things in this situation, but on some level I feel like that's going to push him to change his way of thinking faster than anything else might, especially if he's refusing therapy.

Are there any times where he's threatened to hurt you?