Okay here's a pretty late update. I've been sick for the last week or so, though I am happy to report that I seem to be improving at this point. Last weekend was rough as I had to bail two miles short on my planned 15 mile long run. I knew that I was sick so I was going at a relatively easy pace; but still, after 13 miles I had to pull up and walk the last 2 miles home.
My situation has improved a lot this week. I've regained most of my health, and with that has come my speed and endurance. I completed a 12 mile run with 7 at tempo pace last week, and that went really well.
Looking forward to finishing up these last 5 week or so of tough training before taper-time.