I'm having a second colposcopy...what does this mean?

In the fall of 2010 I had a pap that came back with abnormal cells so I was told to come back for a colposcopy. The results of the colposcopy came back saying I had CIN II-moderate dysplasia so I had to come back yet again and have a LEEP. I was 23 years old at this time. After the LEEP I come back for a pap 3 months later, everything was normal. Then a year later I had another pap...results came back normal. Now I just had my yearly check up with a pap and was told it came back abnormal and that I need to return for a colposcopy. I have that appointment tomorrow and I'm nervous. I went through all of this 3 years ago and it was horrible, I thought it was done and over with but here I am again. I'm hoping that the colposcopy doesn't show anything and another LEEP isn't required but I'm preparing for the worst. Why have the abnormal cells come back? What if another LEEP is needed? Are there any other ways to go to treat this so I don't need to do this all over again in the future?