Are there any exercises or treatment to help one improve short term memory function?

I was in a coma for 9 days in 2004 and my memory was messed up right after I came out of it but I thought it would eventually return to normal. Because I remembered what led up to me being comatose about 2 years later. Instead its been progressively getting worse and its literally driving me crazy. So please, if there are exercises or techniques to rebuild or retrain my memory please share. I am desperate so I will try anything!