It can be hard to wrap one's mind around the fact that God both injures and heals. (Job 5:18)

There is for sure a greater purpose for our suffering which goes beyond our understanding as you already mentioned.

However, I do believe from my own experience that all that we suffer here serves the purpose of sharing in Jesus' suffering in order to become "Christ-like", to learn what life is really about, and to be able to enter heaven where there is no more suffering, and to be more compassionate and a help for others who suffer as well.

I suppose that's why I admire you for your trust which amidst suffering is so hard.