What good is God?

I was raised Christian - Mormon to be specific - but that went away pretty quickly as the schizophrenia started to really take hold in my late teens and early 20s. I became a pagan with mostly Wiccan leanings and that has served me much better. For one thing, it gives a place for the voices in my head. It gives reasons for my hallucinations and delusions. It made me feel less isolated and more in control.

In the past year or so even that faith has wavered. I am still struggling with the idea that there can be any benevolent creator or creators who would do such horrible things to his/her children. Of course, it doesn't help when people keep trying to placate me with inane sayings like this one:

When you are going through difficulty & wonder where God is, remember that the teacher is always quiet during the test. 

What kind of bullshit is that? This isn't a math quiz I'm going through, here. I'm physically sick and mentally ill and the reason there is no end in sight is because this is some kind of cosmic ACTs? It's like those stupid saying that tell you that God never gives you more than you can handle or the door never closes without another opening. Either those are a load of crap or God is actually a sadistic bastard who likes to sit up on high and see how long Sisyphus will keep pushing that boulder before giving up and flipping him the bird.

Of course, this has led to one of my major delusions: I did something extremely horrible in a past life and am paying off the Karma in this one. In my saner moments, all I can think is that God or the gods just don't have any power to help me at all. Either way, it's disheartening to think I could be going through all of this and have there not be a reason for it.