I would like to know the difference between "1"and "2".
1. I'm upset when you come home late.
2. I'm angry when you come home late.
Disclimer: I'm no teacher
Well, upset means agitated, with elements of concern and anger mixed in.
So I'd say #1 expresses more that they were also concerned or anxious because of the person being late, while #2 only expresses their resentment/anger at the persons lateness.