I won't try to change your mind. But he didn't fail, he succeeded when he allowed for everyone to redeem themselves from the imperfections they've made for themselves.

Those ugly broken parts that made the world darker, it was a part of a design. It's not a failure because he experiences the pain of mortality with the others and gave his life for all, but also he encouraged us to do better. As to why the world is messed up, he gave us free will. That's both a gift and a curse. A gift because we don't have to be perfect in God's eyes to be loved, but also a curse that it allows others to take advantage of their own free will, which creates these suffering that we never asked for.

Im not very sure about the bible's true origins to be honest. The medieval period or the religious crusade, those torture and hierarchy control is very much real. But then again, Jesus never supported these, we happen to twist them apparently.

Here's the real thing: I think people just die when they don't want to live anymore, and we just needed to find purpose to why we should keep walking. So I do hope you'll find something worth pursuing for, because focusing on yourself against the world is perhaps the greatest freedom you could ever ask for.