It does get harder. I've been writing a blog for five years now and it's like the wells are running dry. Auden has a neat little poem about being in this situation. I used to have the book but I think I sold it or gave it away- so I'll paraphrase. When the water table sinks and the rain dances don't work any more you switch your strategy and practice "dry farming" (whatever that is). Late Auden isn't as compelling as early Auden, but it has a scratchy, self-deprecating quality I like. He wasn't as good a poet in old age as he was in his youth, but he was still something.
The harder it gets, the harder you have to try.