I Have A Problem With My Ankles. My Ankles Seem

I have a problem with my ankles. My ankles seem to give away making it seem like my foot or feet no longer exist. As I'm walking I get a pain in one or both of my feet at the bridge where the top of my foot stops and my leg begins, like a half a circle ending at the bottom of my ankles. It creates a quick sharp pain and I have a sense of falling as though my feet no longer exists. I have fallen twice in the past two weeks. I now walk with a cane for support, but when both ankles give out a cane doesn't help much. Can you tell me what is possible wrong?