Running with Achilles Tendinitis?

So here's my situation, just today I ran at my State Open Indoor Track Meet in two races (4x800 and 4x400). Yesterday my Achilles tendon started to bother me, but this being a very big meet I did not say anything to my coaches until AFTER my races today. Tuesday (3 days from now) I have another big meet called "Eastern States" that I really want to run in because we have a chance to do very well in the 4x800. The Achilles pain did not affect my actual race, but it does hurt when running normally, walking up stairs ect. Nationals is in about three weeks. Basically I want to get this thing as calmed down as I can for Tuesday THEN I can give it the rest it wants. What is the best way of going about this? Sitting this race out is a LAST RESORT. Any advice would be greatly appreciated. I've been icing the crap out of it, taking lots of advil, and I will rest it tomorrow completely. Is there anything else I can do???