I agree, scrap any single run more then 12 miles, at least for now. They just tire you out too much, and if you hit a wall at 6-7 miles (which may happen after a few days, trust me),finishing up that last 5-6 miles could leave you injured if you loose form and start to overstride, get sloppy on the downhills, etc. The 20-22 milers will crush you right now. That's basically what you were doing over 4-5 days during your previous workload. If you REALLY want a high milage day then split it up into 5/5/10 (say 6am, 10am and 4pm, kenyan style).
The easiest way to do 80 miles a week is running at least 10 miles a day but no more then 13 and double nearly everyday. I don't think I've had a run over 8 miles yet. Last year when I was doing a few 15-20 milers a week but also taking a couple days off a week, the legs tightened up a lot between runs. With doubles they just don't have as much time to tighten up. Run short and often, and if you are feeling good run fast the 2nd half of a run (start each run slowly, even if you feel ok).
And yes, you should be eating like an animal right now, that's one mistake I've made in the past couple weeks, sometimes I would only eat one or two real meals a day because I would just not be hungry when I would try and eat right after a run. So what I would do is have a gatorade and a protein bar, which I think is ok. Just try and force the food down, if you don't you will regret it later if you don't. Going to bed hungry when you know you have a run in the morning isn't fun.