Have you noticed that yoir state of mind influences presence and quality of the morning wood? I just recently started to have morning woods more frequently, after doing nofap. But it seems that when Im depressed, I rarely get morning wood or its very subtle (like 20-30% erection). And then when Im feeling good and happy morning woods are hard and frequent. Or is it because when feeling good my sleep is also better?
I think it's a combination of sleep and stress, an assortment of other factors you aren't even aware, and how all of those things interact with one another. The mind is the body and the body is the mind. It's all related.