Re: what does it damage?
Ok, this is a modern day life problem. All animals nap in the afternoon, we did too. Fortunately, in some countries this is still true, afternoon ciesta, but the computer age is killing that as well.
Circadian cycle is easy to fix, but takes hard work. First, you need to have nice quiet, dark room without electronics wired everywhere. If you can get grounded sheets that will help.
Second, 2 to 3 hours before going to sleep you must have a meal with good fats.
Third, find a way to calm your self down before you go to bed, read a book, meditate, write your daily log, and drink two cups of warm water, then go to sleep controlling your thoughts, must think about happy things.
Fourth, if you cannot fall a sleep, stand up from your bed and walk for five ten minutes.
Sleeping time should be consistent everyday, rain or shine. I am in bed by 9:30pm. Your body hast to rest when your liver starts its cleaning job, say about 10 pm.
Your body will get used to this and it will become automatic reaction for you.
I hope this will help your morning ED. It should be reversed, you should have the best flow of blood to all organs including your genitals in the morning. Best time for sex should be 4am when erections are very heightened.
If by changing your sleeping pattern does not help then read Dr. Ignacio's book...NO, nitric oxide to help heart health and ED.
Be well.
Archus