Look at the second phrase in verse 17, "because of your hand upon me I sat alone." Whoa. Not only was he committed and delighting in the Word in the face of a culture that was adamantly opposed to that Word, but that commitment completely isolated him. He was literally alone against his world.
If Jeremiah were to gauge the effectiveness of his ministry by the number of people who responded to his message he would have quit in despair. But his effectiveness was not a function of measurable response. Rather, Jeremiah's effectiveness was measured by whether he was doing what God wanted him to do. That was all that mattered.
There have been many times that I have been tempted and have measured how I was doing in efforts to reach my kids or other men by how they respond. Wrong measure. Like for Jeremiah, the right one is am I or did I do what God wanted me to do.
The tacit assumption is that I have asked in the first place.