These are familiar problems caused by pacing and racing.
The experiences you describe - in particular, bad run, but surprisingly good time, suggest you are actually running too fast without realising it. Perhaps because you have just run a race, or more likely because you are getting fitter now, it suddenly becomes hard to slow down in training. But you really must do it. Not to do so is a classic training error.
It is extremely tricky to get the pacing right at this stage. I had the same problem in almost exactly the same week of marathon training last winter, when I wrote about "The seeds of doom"
http://www.runningcommentary.co.uk/forum...eadid=102.
Having run the race just recently, you are also likely to feel sore, heavy-legged and a bit jaded for a while. You've already experienced the upside of racing, through increased confidence, ultimate speedwork, and just having a good time. Now comes the downside. It is why some people recommend that you don't race at all whilst marathon training. I wouldn't go that far, although I have also overdone it in the past, notably when I ran the Bath Half Marathon
http://www.runningcommentary.co.uk/forum...eadid=158, and then felt T-I-R-E-D afterwards
http://www.runningcommentary.co.uk/forum...eadid=161.
The solution is either to take a step-back week after a race, or, it that doesn't fit, simply to take it really easy in terms of intensity and self-forgiveness. You've got to cut yourself a lot more slack over the next few days. That way you can gradually recover over a week or so, back into the normal training rhythm.
Finally, as I mentioned to Andy once, just because I can sometimes come up with advice, that doesn't necessarily mean that I always follow it myself..... It is surprisingly difficult to back off, even when you know you should. Sometimes the adrenaline can take you too far. But perhaps just understanding the root of the problem will take you half of the way towards finding the best solution for you.