Suggest Treatment For 8.6 Mm Thick Glass Stuck Under Metatarsals

Hi, I recently stepped on the stem of a broken wine glass and it went DEEP in to my foot. I've been to the local ER 3 times, the first time my foot was cleaned and stiched up. I woke up with severe pain and went back. They took a x-ray of my foot couldnt see anything and then a cat scan revealed a 8.6mm chunk of glass with some shards right under my metatarsals. The doctor who looked at it said surgury would be VERy risky since the glass is very close to a nerve and told me it might be better to just leave the glass in my foot. I asked him if I decide to leave this third of an inch chunk of glass in my foot wont it cause more damage being glass and that I am also a diabetic. I'm going to get a second opinion from an other doctor to be sure.