You are in luck, because I have dealt extensively with calf/shin issues! Since you are a heel runner, I take back what I said about recommending hills - especially since we are dealing with a calf injury. I would also recommend against the plan you posted previously, with this new knowledge about your injury. People who tend to heel strike often run into trouble with shorter, faster repeats because these workouts force you up onto your toes and overwork your calves. You don't want to re-injure your calves with too much sprinting, so it may be beneficial to look at other methods of recruiting fast-twitch muscle fibers. Lifting will definitely help with your leg-speed and kick, and it will be much less risky than doing all of those reps :)
The elliptical may be an especially useful tool for you. I know it sucks a lot, but you'll only have to do it for a month and it can really improve your fitness with virtually no injury risk. Cycling is also an option, but is not as similar to running.
Keep your long run, as it sounds like distance isn't really the problem for you. Try to keep things flat for awhile (even gradual ups and downs can really aggravate a calf injury.) You could even mix cross training and running to get all of the aerobic benefit without the extra pounding (say, run for an hour and then elliptical for an hour right afterward.)
A strategy that has worked for me when I am trying to get in shape really fast (like right now, actually) is to focus my training efforts on what I feel is my strongest point. This may sound counterintuitive, but your strongest area of fitness is the area that will generally respond the fastest to your training. You say that endurance used to be your weakness, but now your finishing kick is what gets you. Based on this information, it seems that you are more of a strength runner (can really hammer a pace, but not for the longer distances and pace changes may be difficult for you). If this is true, I would focus your training efforts on intervals of 2-5 minutes with fairly short recoveries. It may be beneficial to do these on grass. Even though you'll be racing on a track, working out on grass will be just fine. It may even make you stronger! It is also a good idea to just run for time at first and not worry too much about your actual pace. You don't want to get discouraged over a slow interval time, so just focus on running hard. Do your tempo runs on the elliptical or in the pool and maybe one more interval workout on the elliptical late in the week if you are not too beat up.
A sample training plan could be:
Day 1: w/u 2-3 miles 6 - 8x3:00 (on grass) w/1:00-1:30 recovery, c/d 2-3 miles. Add in elliptical if you are trying to bump up your volume.
Day 2: Easy 4-9 miles (a large range, I know, but it all depends on how you feel after the intervals.) If you want, you can do an elliptical workout in the PM on this day, maybe 20:00 tempo or a ladder workout.
Day 3: 6-10 miles + elliptical if you feel so inclined.
Day 4: AM: w/u 2-3 miles, 1:00, 2:00, 3:00, 5:00, 3:00, 2:00, 1:00 ladder w/ 1:30 rest between everything (this means you'll be running the 1:00 ones pretty hard.) 2-3 mile c/d. PM: 30-60 minutes elliptical
Day 5: AM: 4-10 miles easy (if you are sore, you can do the equivalent time on the elliptical.) PM: elliptical workout: 10x 1:00 hard/1:00 medium. This is a good little fartlek workout that I use when I am very tired and just need to get something in.
Day 6: Long run of 10-16 depending on how long your long runs were before you got hurt. If you want extra aerobic work, add some elliptical on to the end of this run. If you are feeling sore or beat up, replace this run or part of it with cross training.
Day 7: Rest or cross train.
Notes: add strides, weights and core work wherever you feel they fit in.
It is okay to do workouts on consecutive days, as long as one of the workouts is cross-trained. Don't feel like you have to work out hard every day of the week. It may seem like this will get you in shape faster, but it will just wear you down. Take your recovery days as seriously as you take your hard days, and you are looking pretty good.
Also, something that may help with the calf tightness is self-administered ART (active-release-therapy, I think). Basically, you use a tennis ball or baseball to put pressure on muscular trigger points and this helps release the adhesions and knots in the muscles. Start by lying on your floor, face up. Put the tennis ball under the meatiest part of your calf, right in the middle. Roll it around until you find a tender spot. When you find a tender spot, cross your other leg over the leg being worked on and use it to push your calf into the ball. Just hold this position for awhile, in the same spot. Your calf may start to cramp, but be strong through this - it is part of the releasing process. Eventually, the pain will subside and you will feel an "untwisting" sensation in your calf muscle. When this happens, you can move to the next knot. If you would rather use your fingers to apply pressure to the knots, that is okay too. I just prefer the tennis ball because these treatments can take a long time and my hands get tired :) Do these treatments after you've done your run for the day and try not to be too active on your legs for at least a few hours after you do this massage on yourself. You may be very, very sore from this at first, but usually the soreness dissipates after about 12 hours. It may linger around for a whole day, but really it should feel better overnight.
Wow, okay, now that I have written you a book, I think I'll go to bed! Please let me know what you think about these suggestions and if they could work for you. Also, if you have any more calf-injury related questions, I am your go-to person :)
Here's to big comebacks in a short amount of time :)