Dark,
I had same experience playing BBAll. 10yrs ago. MIne was I pulled the tendon out of the hill. I had a reattachment surgery and was out of comission for 2 years. NO PLAY, I only thought was a tendonitis first, but get some xray, it will get worse if not correted timely.. but if you can raise the front of ur feet up and down fully i hope it is only a tendonitis..
Only today have I read this reply. Yes poordoy, a friend of mine, a doctor, suffered the same fate as you. He snapped his achilles tendon and required surgery. Everyone who was there would swear they heard a very loud snap, like a branch was snapped in two.