nipping an injury in the bud

This question is specifically about my achilles, though I guess we can substitute any other part of the lower extremities. Here's the background from Sunday:http://www.beginnertriathlete.com/discussion/forums/thread-view.asp?tid=176616&posts=9&start=1I took yesterday off. Today I planned on swimming but it was too rough so I switched to an easy hour run. No acute pain but it was a bit sore and tight by the time I made it home so I iced it for 30 minutes. Brought the ice pack to work today too. The muscle behind the achilles feels a bit inflamed and has kind of a "starchy" squeaky feeling to it when I elongate or contract it. There's definitely something off. I'm not really sure how to deal with this injury because it's from use and poor mechanics rather than some event, like twisting an ankle. My guess is that the more I use this muscle the more trouble it will give me. Of course I'm in a build 2 for an HIM in 10 weeks and training at a higher volume than I ever have before, so I want and "need" to get out there and train. Of course the last thing I want to do is create a nagging injury that will turn the fun I'm having training in to a nightmare. So what's my move? Don't train? Train less? Train smarter? Switch from bike/run to an elliptical machine for a week? Advil? Ice? Heat? I'm clueless on how to mitigate a use injury when I gotta use that muscle for 10 more weeks. The one thing in my favor, I think, is that it's a brand new injury and isn't really debilitating so I think I have the opportunity to shut it down early if I can come up with the right method.