"I just can't take this any more." Have you ever told God that? And has it ever not gone away? I have been there, and God has brought me through. But He did not take the problem away. Romans 8:28 unfortunately has become a cliche. Something that rolls off the tongue of those who do not want to take the time to care. But it holds an important truth: that while God is in control of our lives, His goal is not to make us happy but to conform us to the image of Christ (Romans 8:29,30).
Now pressing this home to a person undergoing great suffering may not be the best strategy. (I know you are miserable now, but just think of how much better a person this is going to make you.) But on sober reflection, this is a helpful perspective. If we see the basic focus of our life as us and God as someone who is there to make us happy, every problem and setback seems enormous. But if we understand that we belong to Another (1 Corinthians 6:20; 2 Timothy 2:3,4) and our job is to carry out His purposes in this world (Ephesians 2:10; 2 Corinthians 3:4-6), then we will look at our difficulties with a different set of eyes. This will not take the pain away when we are in a position where we feel we cannot take it anymore. But in the long run it will help us see our troubles as part of the plan of the One who controls all things (Ephesians 1:11).