The thought of suicide does not usually arise "rationally", but usually due to anxiety created by the context/environment/society. There is no rational argument that ends with "Therefore, die" just like there ain't any that says "Therefore, live". Rationally, living on and "fixing things" seems like a better way to alleviate the suffering, suicide is a very crude and dumb measure, eliminating any possibility of suffering and "non-suffering".

If it was a purely random or logical decision how can you explain the differences in suicide rates among different groups (e.g. males)?

> you have to understand wanting to kill yourself

I 'm willing to bet that everyone has had that thought at least once in their life.