What shoes are you wearing? If the blisters are that bad, maybe it's time to find a different pair or maybe different socks. I'm actually about to start hunting for a new pair myself, Nike has changed the Free just enough that I'm blistering at the arch and I didn't last year in the same shoe. Running is actually my cross-training, but it's one of the easiest stress management tools I have, too. BTW, have you read The Oatmeal's book yet? He talks about running the same way you do
My Marine Corps Marathon actually rocked. This is the first year I've been healthy through the whole training cycle and the weather this summer was great. (I am pointedly not remembering the 18 mile planned run that ended with heat exhaustion at mile 12 while I was 4 miles away from my car.) This was the first race I ran with a goal time and pace strategy. Last year I finished in 5:15 and once I finished the Navy-Air Force Half with a 15 min PR, I decided to set my goal as under 5 hours. I used a pace calculator to figure out 5-10-20 mile splits for 4:58 and 5:05 and wrote them on my arm. My coach wanted us to focus on big splits rather than looking at pace each mile and I think it worked well for me.
I started slightly slower than my planned overall pace, which was pretty easy because of the crowds the first couple of miles, and the dude who thought he was going to get around the slower people by bounding gracefully over the median and through the grass - which ended with him twisting his ankle and rolling into a sign post. I stopped to help him up and see if he was okay, then continued. I walked all the waterstations and tried to stay consistent otherwise. Actually felt good but my right foot started to blister around mile 9, which was completely negated when a friend surprised me by perfectly timing her break from work at the Kennedy Center (mile 10) and giving me a big hug. I smiled all the way through mile 15, when I stopped at the medical tent and grabbed a couple of band-aids. I figured that it was better to stop and take care of the blister than to risk not being able to finish because of my feet.
I ran into friends at miles 17 and 25, which helped to no end. Miles 23-25 for Marine Corps go under the freeway and around the Pentagon parking lots, there's nobody there and it's hot and you're feeling miserable - that's about where I started losing motivation and aside from the mile where I stopped for band-aids, mile 25 was my slowest. I did marshal enough energy to run the full hill up to the Iwo Jima Memorial, which I didn't quite manage last year.
End result - 22 minutes better than last year and 6 minutes faster than my goal time. Last year I'd battled Achilles tendinitis in both feet, plantar fascitis that likely came from running through the tendinitis, and a summer so hot that at least three long runs had to be cancelled. So, being healthy and cool made a huge difference. That meant I did at least one run on my own during the week, plus a track workout and long run with my distance training group. I think having a coach and being able to run with people better than me really helped me push past my self-imposed limits.
As far as running with the Marines - it's an amazing experience. And DC does races well in general; if you can't get out for the marathon, we've got a lot of awesome races in the 10 mile range including the Cherry Blossom 10 miler, George Washington Parkway Classic (10 miles starting at Mt. Vernon), and the Army 10 miler. Cherry Blossom and ATM both get you lots of monuments and the best vistas of the city and pretty good crowd support. The marathon is kind of the marquee event for the city's road races though - Rock Creek Park (miles 6-10, out and back) is one of the most beautiful parts of the run and you don't expect the parkland in the center of the city. Then along the Potomac River past the Kennedy Center (mile 10), Lincoln Memorial, and around Hain's Point (Miles 11-15. I'll be honest, lots of people hate this 4 mile loop because it's hard for spectators to get to and can be quiet - but the Marines spice it up with cool aerial set-ups for the photographers and the Cliff Shots station). Out of Hain's Point, you head down and then back up Independence Ave past the Lincoln Memorial, then up around the Mall and back down - turn around is around the Capitol Reflecting Pool. After mile 19 is the hardest stretch of the race - a friend calls the 14th St Bridge the "14th Street Soul Sucker" because it's so looooong and there's no shade or crowd support since spectators aren't allowed beyond a certain point. You see lots of people broken down along the medians at that point. Once you get off the bridge at mile 22, you go into Crystal City, which is a soulless outpost of commercial buildings and high rise apartments, until you get to mile 24, which is where I started losing steam. Mile 25 picks up as you get back onto the highway where the start was and crowds re-appear. The mile 26 marker is the point where you turn left and run up the hill towards the Iwo Jima Memorial and it doesn't matter how many training runs you do up that hill, it's HARD during the race.
The race is really well organized, and there are Marine volunteers (and other volunteers) stationed all over the place to motivate you. Marines line the final .2 and shout encouragement the whole time. DC is a big running town and our running stores and groups do a great job of setting up cheer stations and otherwise encouraging people. Those who aren't running get out on their own and provide excellent necessities like Swedish fish, pretzels, and beer. This year I even felt strong enough to take a beer shot at one point, and I took oranges, too. I'd do the beer again, but not the oranges - I spent 16 miles trying to get the sticky off my fingers.
So, that was long. Run Marine Corps. It's a lottery now, but Team in Training was recruiting fundraisers for their team all the way towards the end of the summer and I suspect some of the other charities were, too. If you can't do that, the George Washington Parkway Classic is often open until a week or so before the race, and so is the Navy-Air Force Half, which has a very similar course on the DC side of the Potomac, you just miss the (sort of meh) stuff on the Virginia side of the river.