This is the 849th most frequent Chinese word.
困
"困" means "sleepy" or "trapped."
困 in this sentence is used as an adjective meaning 'sleepy' or 'drowsy', describing the speaker's physical state.
我感到很困，所以早早就睡了。
I felt very sleepy, so I went to bed early.
困 is used here as part of '困惑', which means 'confused'. It conveys the state of being puzzled or uncertain.
在山里迷路的时候，我感到有点困惑。
When I got lost in the mountains, I felt a bit confused.
困 is used as part of '困住', meaning 'to trap' or 'to confine', illustrating a state of being held back or hindered.