Emotions are there to help us, and they serve a purpose!
It's totally normal to feel certain negative emotions from time to time. What's important to remember is that these feelings can actually be a sign that we have some physical or emotional needs that we haven't yet met. And the good news is that we can take a moment to identify what those needs are and then find ways to satisfy them. There are so many ways to do this!
Once you've identified the need (this might take a little time, or it might be pretty straightforward, depending on the situation) and met it, the signal for those negative emotions will start to fade away.
So, in addition to "controlling" our emotions, we can also "recognize" and "discharge" them. It's great that you've already recognized them (as evidenced by your ability to name the emotion as "irritable") and sought help on the road to discharge (as evidenced by posting a request for help).
It's totally understandable that you're asking "why." It seems like you're looking to find the root cause and solve it at the source, and there's absolutely nothing wrong with that!
I have another thought for you that I hope you'll find helpful. Sometimes, we don't have to worry about finding the cause of a problem (Why) to solve it (How). For example, I don't know why I'm often irritable, but I can improve my mood by doing something that calms me down (such as going for a walk/exercising/sunbathing/listening to music/eating something delicious and drinking something tasty/reading a book/other...).
I really hope you find a method that works for you!


Comments
I understand how tough it can be when emotions get the better of us. It sounds like you've been under a lot of stress lately, and it's affecting your relationships with your family. Maybe finding a way to channel that frustration could help, like talking to someone or engaging in a hobby.
It seems like you're really hard on yourself for losing your temper. We all have moments where we wish we had handled things differently. Have you thought about ways to calm down in the heat of the moment? Deep breathing or stepping away for a bit can sometimes make a difference.
Feeling irritable and snapping at loved ones can strain those important relationships. It might be helpful to apologize when you feel you've overreacted and work on strategies to manage your anger. Sometimes, just acknowledging the issue is the first step toward change.
It's not easy to always keep our cool, especially with family. I wonder if there's an underlying cause for your irritability that you could address. Perhaps getting more rest, exercising, or even seeking professional advice could provide some relief and improve how you feel.
Shouting at family members can hurt everyone involved, including yourself. It's great that you're recognizing this pattern in your behavior. Maybe setting up a support system or practicing mindfulness could assist you in managing your emotions more effectively.