4 days ago a began having extreme sinking feelings when I walked, as if my feet were sinking in quick sand and my feet feeling weighed down by bricks. It came out of nowhere and has continued each day for the past 5 days. I m 26 years old, have no medical problems and no real problems in my life. I did get stung by a jelly fish at the beach right before these symptoms started, however it s been 5 days since then and these symptoms have not gone away. I do have bad sinuses, and also drink a lot of pepsi each day, so I don t know what could be causing this.. Diabetes? Stress? Sinuses?