Personally, yes, I would just do the 6.5 next week and then skip the 3 miler. Or don't skip the 3 miler, but push everything back a week and drop the 14 miler at the end. I don't think I've ever followed a training plan exactly as set out. Something always comes up (injury, vacation, sickness, bad weather) that makes me skip runs and fiddle around with the distances. Galloway has you topping out at 14 miles, but many (possibly most) half marathon plans for beginners don't even go the entire distance during training. My personal rule of thumb is if I manage at least a 12 mile long run before the race, I'm good to go. I may feel like crap afterward, but the excitement of race day will carry me that extra mile. The Galloway training plans are great, I'm doing a Galloway plan for this race myself, but there are many different ways to approach training for a half marathon and you shouldn't feel that if you can't run the plan exactly as written that you won't be able to run the race.
Sorry you're dealing with an injury at this point. I know it can be really discouraging. I don't think I've ever gotten through an entire race cycle without some sort of injury, and every time I worry that I'll miss the race, but that hasn't happened yet. We still have plenty of time before the race. Better to take some time off now than push yourself and realize a few weeks out that you won't be able to run the race.