Foot injury

I injured my foot on March 12,2015. I slipped wrong on a stair. I have had 2 sets of x-rays and an MRI, 3 weeks of physical therapy 3 times a week, 5 weeks in a air cast(which has now been off for 2weeks) as well as a second opinion but my foot is still hurting me. Both Docs say nothing is broken and all one saw differntely was a calcium deposit around my anke which could have been there before. They are just writing it off to soft tissue damage.
The pain is on my right foot the right side from about half way down my foot to around my ankle. it hurts when I try to take a full step during the pushing off motion on your toes.
I walk with a constant limp and can only wear a sandle and my ankle is now sweeling at night ( which its never done before even when the injury occured). Needless to say I am frustrated, after 3 months will no visible injury what could possibly be wrong.
I have done everything the drs have said to the letter and just don’t feel like I am making any progress…..any insite you can give me would be much appreciated.