First of all: Congratulations man! You made a great choice going to Freiburg!! I stayed there for a year and everything was great there, lots of students, parties, a great place for living, lots of things to see and do in the surroundings....
Unfortunately, gay life is very limited there. There are not any gay bars. Long time ago there was one called "räng teng teng", nowadays is not, but still can be found some. Always has old-school music but the crowd is young, mostly students. I recommend it.
There's disco called Parabel Club (http://www.parabelclub.de/), it's very new, just opened when I had to leave, there are gay parties once a month I think. Another one is Waldsee, it's not in the town center but also organizes a gay party once a month (I think it's run by the same community of Parabel).
I saw you opened an account in GayRomeo, great choice.
If you need some advice in general about Freiburg, just ask me. Enjoy it!!