Foot trouble?

I am pretty active with climbing and hiking but then i caught the tri bug. So about two months ago i started a regular training program of running, biking, and swimming. After a month or so, my achellies tendon got a little sore. I changed from running to walking and upped my bike time. That went on for a few weeks and my tendon felt fine. I had planned to start training harder on Monday(tomorrow) but when i got up this morning i could barely walk? About an inch off the floor if im standing flat, my tendon is sooo sore to the touch. Dosent hurt at all till i put weight on it. I can flex my foot up and down but it only hurts when i flex it up stretching the tendon. The last workout i did was biking Friday. Could this be something other than tendonitis? What would cause it to hurt so bad when i havent done anything that should have torn it? I just noticed my ankle is swelled a little to?? I can sqeeze and rub all over my foot/ankle, and tendon but it only hurts when i push straight in on the tendon right above my heel? Any one got any ideas? Thanks for any info. I most likely will go see my Dr. next week but I'm just curious if anyone else might have had this happen. Thanks again....shane