You put too much of it and the glue that remains uncured underneath the edges (because uv light doesn't reach it), found its way to the backlit of the LCD. Th glue stays between the lcd and the backlight panel and produces the cloudy image.
1) carefully remove the backlight and clean it with alcohol (ridiculously time-consuming)
2) buy a backlight panel or find a broken screen of your model phone, remove the backlight, remove your backlight panel too, clean the back of your lcd after removing original backlight very gently with a very soft cloth and alcohol and then install the other backlight on your lcd.
NOTE that any debris that stay between the panel and the lcd will produce a dark spot, so make sure everything is crystal clean before installing the new backlight.