Sounds like you are getting the hang of this thing, but go easy on yourself. It is very difficult to detach.
You are right about the endorphines! So what is your running pace? I am a very slow runner - I can run a 10 minute mile on a 5K but am down to an 11 minute mile for 10K's. But, I do not run to compete with anyone other than my own demons. H is a much faster runner 7.5 minute mile on a 10K. As his depression settled in more and more, he became fanatical about running. I now think it was to get the endorphine rush to ward off the sadness and despair.
I ran Wed/Thursday and am resting today (unless of course I get mopey, then I will make myself run - part of my new deal with myself). I will run again Sat/Sun.
What are you doing to entertain yourself this afternoon?