I'm not able to concentrate on my work. due to that my performance is going down day by day. I shouted at people without any reason. I lost my control over small things. How can I cope from these things?

These are signs that you may be depressed, people who are depressed will get moody with the each other and they will actually be less focus on their daily activities

I would recommend talking to someone about your feelings. If that seems too difficult, you can write in a journal or a diary. It's much better to let out your anger and emotions in a book instead of shouting at random people, which can make them confused. You can also take a few deep breaths, tell yourself that it's absolutely okay to be feeling this way. You can also just scream at nothing in general to release any pent up feelings. Punching a pillow also works pretty well to relive stress. Just make sure that you cope in a healthy way and remember, the sun always shines after a storm.