Talk to Psychiatry on Stress

I was under great deal of depression since 4years.but for some months it has been worse. I am imagining all the worst things for my loved ones and my brain is depicting very clear pic of my thoughts.i can see the scenes that never happened in my eyes several times a day.its like a movie my brain is playing on repeat.i am always afraid. Kahin abu ami ki na kuch ho jy.kahin kesi ko chot na lag jy. My sis is pregnant and i am imagining her falling several times when she is walking here and there.i imagine her other kids being hurt.i love all of them so so so much and it is very painful.my brain is always busy even when i am talking with someone about something my brain is busy with another story behind. I am otherwise very confident in front of others.i can notice appreciation in their eyes.i am a very responsible girl as well. But because of all this i am always angry now Please guide me whAt to do?