Without more details about your life, I can only venture a few very general guesses.
Are you getting enough sleep? It’s the end of a semester. Often students, who already don’t get enough sleep, are up very late, finishing up papers and studying for exams. Often they are stressed and irritable. If you aren’t getting at least 8 hours of shut eye every night, you can expect to be irritable.
Are you perhaps depressed about something? Depression doesn’t always show up as sadness. Sometimes, especially in men, the primary symptom is irritability.
Do you have something to be angry about but aren’t facing? If you are burying something you really do need to deal with, the anger may be a way you are giving yourself a shove.
I hope this is helpful. If not, do consider seeing a counselor who can hear your whole story. Working together, you may be able to put the pieces together and figure out how to manage whatever it is that is bothering you.
I wish you well.