What Samuel Rutherford cared about more than anything else was teaching and tending his little congregation at Anwoth. But in the political upheaval roiling Scotland, he was among the ministers deemed "unorthodox," so was exiled and imprisoned at Aberdeen, prohibited from preaching. All he could do was write and receive letters.
Today, 377 years later, we see what really happened: God valued Rutherford's efforts so much that He channeled them into a form that would reach far more people than he could in person. Like the Apostle Paul, God constrained Rutherford in temporary physical discomfort in order to give him what he wanted on a scale that he could not begin to imagine.
Don't let your faith crack under disappointments; let God finish what He's doing with you.