Chanji could you try what I posted in my thread? This may or may not work as you have integrated graphics but its worth a shot.
Settings wheel next to play > Game Settings > Additional command line arguments >
-graphicsapi Direct3D12
CaptainJack seems to think that blizzard could do no wrong and it is all the users fault, This fixed my issue from 30 fps back to steady 200.
Hope this helps.