Ex boyfriend/ friends trouble???

I went out with my ex for over a year, he became part of my group of friends and it just seemed natural for him to be in this group. Now a year on I split up for him for being to posessive of me whislt away at uni (even tho i came home every weekend) now the group have totally turned their back on me, they all go out without me, have booked a holiday etc. I feel so upset over this, the friends i have are my main friends, the people from uni live so far away?? I feel totally left out and end up spending many weekends alone now with my family, my other best friends stayed at uni as they all went further a field so havent come home for summer as they are working!!! What can i do?? i know its not long until i can get back to my fab uni life but what can i do for the remaining 44 days?? yes im counting down!!!