A change is needed..

Lately, my weekday runs have been piss-poor.  I do my best running in the morning. I am a morning person, after all.  However, my schedule changes frequently. Lately my first appointment on  my running days has been at 9 am instead of 10. Because of the impeding darkness in the morning, I'm apt to wait for the first break of light now, which doesn't leave me much time. I don't like to run when I feel rushed, and I don't enjoy running when I'm tired after being on my feet all day, stretching patients, and trying to catch people as they struggle with their balance.
So, I've been having to run after work on Tuesdays and Thursdays.  Could it also be that I'm running longer distances on the weekends, causing me to require longer rest periods? I'm not sure. But I go out planning to run a 5k, and poop out after 2 miles. Or plan for a 5 miler, and give up after 3. On Tuesday, I planned for just that. Could not, did not, want to continue after 3.7 miles. I wasn't too disappointed in my pace, but I was mentally and physically wiped. Could I have done it if I had gone out slower? Perhaps. But something has to change with my weekday runs.. or then, what's the training for?
TPP