Hey, I have the same problem :-(. I have done 2 degrees at the same university and know the lecturers and the surrounding quite well. I have been offered a PhD there too. But like you said what will potential employers think if the degrees come from the same university?

Also does it matter to employers where you have done your PhD? For example if two people were applying for the same position but one came from a 'better' institution.

Thanks in advance :-)