GG, has this been a situation for you?
For a few weeks I worked over 100 hours, and I really wanted to play, but just wasn't able to really stay focused on the task even tho I was mentally ready, physically i just was worn out. But it was a temp. condition, once I got back to a normal work schedule, all was well.
As far as cumming, I have experienced release when not fully erect, but only when practicing safe release.