Screen turns off and on. Won’t stay on for more than 3 minutes.

My phone was perfectly fine and all of a sudden the screen wouldn’t turn on. Every time I press the power button or the sensor it doesn’t turn on. It flickers randomly and when I’m on it, it doesn’t stay on for more than a few minutes. I tried the Xperia companion thing and I hard reset it multiple times. Please help I don’t know what to do