I agree with AW, if you don't deal with the cause of the "blister" it will come back as soon as you start to run again. In this case, there are two muscles really involved (gluteus minimus and gluteus medius) and two that are a part of it but not primary (tensor fascia lata and gluteus maximus). Fortunately, when you're doing the treatment for one, you're actually doing it for all four of them.
Take a tennis ball (there are other good balls, but for a while a new tennis ball will work) and put it on the muscle that is on the outside of your hip, between your hip bone and the bone at the top of your thigh (called the greater trochanter). Then lie on the floor and look for the hot spots. You'll find them easily because they will feel like someone is jabbing a hot poker into your hip. Ease into the ball, always only going for "hurts so good," not "I think I'm going to faint." As you lie on it you can add a little more pressure about ever 30 seconds. You'll find that the hot spots are only about 1/4" away from each other so this could take you around 15-30 minutes to completely cover the area.
You may have to do it 2-3 times before it stops returning, and I suggest you check in with it once a week until it's permanently gone. The problem is, it's a repetitive strain injury and since you're still running, it will likely return. But you'll know how to treat it yourself, so it's not an issue.
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