I don’t want to be a downer. But man, are you sure?
Because it is very unlikely. It may be a gradual decline on other areas so you may not even noticed it? As an obsessive person, even i didn’t realize my own changes. This trauma from the disease masks some issues i would say. So, think twice. You have to face with the harsh reality as soon as you can to fix it.
If you have ED, you should also have sensivity loss, muscle and nerve weaknesses, probably prostate issues and related things.
But, you are very lucky if you are really sure that everything is 100% normal except for your Bloodflow to penis. That’s nice bro.
That would indicate a physical problem, maybe get a full MRI on your nerves.