I have been noticing a change in the last month in my ability to get an erection. I find it very difficult to achieve an erection on my own. I am not sexually active, but the frequency of erections in the morning and futile attempts to get one when watching videos on the computer is enough to know something is wrong. Over the past two days this week, I was able to achieve an erection very easily, but since last night, I'm back to nothing. How does this happen? What is happening? Why is it happening? I'm 27 years old.