Achilles tendon rupture?

I think I may have an achilles tendon rupture. Last week at gymnastics I was doing a front flip and landed weird and twisted my foot. I went to the doctor the next day and got x-rays and nothing was broken. The doctor called it a sprain but my heel, achilles tendon, and the area around it hurts really bad and I cant walk on it without it hurting. The pain is like something is stabbing me in the leg. I don't want to waste my time if I don't have anything wrong with me but it hurts and I can't do gymnastics with it hurting like this. I got a brace to help me walk better but it still hurts really bad. HELP I need to do gymnastics!!!!!