Horseshoe Kidney?

I found out that I have a horseshoe kidney. I've been trying to do some research on this without much luck. Does anyone know anything about this anomaly? All I know is that my two kidneys never seperated during utero to cause the "horseshoe kidney" that I have. I've been having problems with stones for the past 2 years. I had a urologist go in to break a stone (he said is was 9mm) that was in the area "between" my two kidneys last summer and a few months ago I was in the emergency room because of more severe pains and they said I had so many stones they couldn't count them all. My family doctor wants me to go back to my urologist, my urologist shoved me off saying they were all small enough to pass.... months later, no stones passed! I still get very frequent intense pain if I'm active that is difficult to get rid of unless I'm laying on the couch or in bed for a few hours to let the pain run its course I guess. I'm without insurance at the moment so am stuck and wondering if these stones could cause kidney problems? Also, what happens if one side fails...will the other side fail too? I have tons of questions and can't find a whole lot of info about this. I'm interesting in seeing a nephrologist as soon as I get insurance again, but that could be a while... so I'm trying to do what I can with learning about this in the mean time.