How do I know what I am acting out on?

It is really hard to tell from the few symptoms you’ve listed what is going on. It could be hormonal teen mood stuff. It could be major depression, I mean you almost meet criteria as far as the symptoms you’ve listed

(1) depressed mood most of the day, nearly every day, as indicated by either subjective report (e.g., feels sad or empty) or observation made by others (e.g., appears tearful). Note: In children and adolescents, can be irritable mood.

(2) markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day (as indicated by either subjective account or observation made by others)

(6) fatigue or loss of energy nearly every day

(8) diminished ability to think or concentrate, or indecisiveness, nearly every day (either by subjective account or as observed by others)

but you really should consider talking to your doctor and/or school counselor. sometimes these symptoms can be caused by something else. either way, if it is distressing or it affects your life, you should get checked out.

You could be bipolar or just experiencing being a teen.