My temper is very short and most things annoy me?

It can be treatable. Major depression, bipolar disorder, spectrum of mood disorder, stressful life situation, sleep deprivation, work fatigue are most common causes of irritability and short temper. Addressing underlying condition can help control these symptoms.
Treat irritability. Irritability can be caused by mood disorders such as depression, mania, or anxiety. It can also be caused by simple sleep deprivation. Make sure you are getting adequate rest-- 7+ hrs minimum of restful sleep per night-- and that you're taking care of yourself by exercising and eating well. Consider medical eval if you are also feeling down/depressed, or have little interest in doing fun things.