Sorry that you are going through this!!
Lots of people don't keep the same friends that they had when they were young---in school we kind of form friendships partly out of convenience because we are all thrown in together!! So whether your BF situation works out or not, don't beat up on yourself!! It happens. You will make more friends!!!
Your T probably just wants to protect you. Your friend may be acting nasty or she could be confused about her own feelings.
First jobs can suck!!! They never tell the new people everything they need to know. Everyone gets so wrapped up in their own jobs they forget what it must be like to be new. Hang in there!!!!