Flickering pixels rainbow at all of the screen AOC AGON AG273QCX

Hi

Today i hit my monitor by a book at the corner of LCD. Then all of my screen started to display a flickering red or green pixels like on the picture. It looks worse at dark pictures. In bright there is very hard to see. There isn't any cracks on glass. Sometimes the monitor turns off by itself for a moment. Is anybody know what could be wrong?