irritating; irritated; frustrating; vexing; (feeling things are) not quick enough; (feeling) too slow-going; (feeling) impatient; tantalizing; tantalising
うまく伝えられなくてもどかしい。
It's frustrating that I can't convey it well.
回線が遅くて、動画の読み込みがもどかしかった。
The connection was slow, and waiting for the video to load was frustrating.
作業は順調に進んでいるので、もどかしくない。
The work is progressing smoothly, so it's not frustrating.