My PC screen crashes after 10 min of playing overwatch

Before all, sorry for my bad english. Im an overwatch player and since some days i had one issue that stopped me for playing overwatch. I launch the game and everything is normal but after like 10-20 or even 5 min of playing a quick or ranked game the screen turns black, the sound starts to bug and the pc does sounds of devices disconecting and there is nothing i can do in that situation that restart the computer manually. 1 thing that you have to know is that there is a sign that may have relation with this problem https://imgur.com/a/dnEvp i dont know what this weird power sign is. I hope some of you can help me out BECAUSE I WANT TO PLAY JUNKRAT OH GOD I LOVE HIM SO MUCH. ty