Will my girlfriend end up leaving me?

My girlfriend is going to another school next year, she says that she belongs in a “mainstream school”. There are going to be way more people around. What are the chances that she is going to leave me? Something just tells me that someone there is going to win out over me, so should I even bother staying in this relationship if this is going to end up happening? I don’t have a cell or anything so that we cans tay in contact like other people might and I have a bad feeling about this.