Redo "Bad" Tempo Run or Press on?

Newbie, here. So glad to have found the log/site and this blog. I could use a little help...

Okay, today's run really stunk. Missed Tempo pace by ~2 min/mile...had to walk almost the whole second half (of total 5mi). Lungs and overall energy felt fine, but the legs just didn't want to go--they were still sore from a 2-miler on Mon after Sunday's long run (7.4mi)--that's never happened in my training before. There are a lot of things that probably contributed to the perfect "bad run storm" like:

1) a long run on Sunday

2) a short easy run on Monday. this was the first time i tried an easy run on day immediately after long run. I felt fine during the run and the rest of the day. Tues i was surprisingly sore in my calves, feet, hips and shoulders. (comments on this?)

3) lack of enough sleep since at least Sunday

4) a couple of beers Tues night, leading to

5) underhydration, though i tried to "water up" this morning

6) probably not enough nutrition in the morning

7) heat in mid-80s with high humidity

So, i feel confident i understand the error of my ways. And I still have a few of questions.

First, since this was a tempo run, do i do it over another day or skip it? What about the rest of the week? Schedule:
- Thurs, 2 mi easy (im not so sure it's the right idea...i'm feeling VERY stiff and tired)
- Fri, rest or x-train
- Sat, long run, 7 mi (this will be the third one at this distance)
- Sun, rest

And second, how much should i eat in the morning before a tempo run? i have a tendency to get nauseous if i have too much fat or protein, so i always err on the side of fewer calories (plus my demanding job makes it difficult to eat--even at my desk sometimes).

Thanks in advance, Sasha, et al!
Kelley