Exact same problem, it's quite annoying and quite frustrating, I've tried deleting the sun textures plus experimenting with the enbeffect.fx file, still nothing.
I've accidentally changed a lot of the ini settings for mods and performance in the SkyrimPrefs.ini in the C:/Program Files (x86)/Steam/Steamapps/Common/Skyrim/Skyrim" folder and not Documents/MyGames/Skyrim which have the separate Skyrim.ini and the SkyrimPrefs.ini. In that case do I need to fix it by putting a SkyrimPrefs.ini backup in the Skyrim folder located in my program files and add all the tweaks to the skyrim in the Documents folder, or can I leave it be?