professional vs personal

As most of you have probably noticed, a lot of the people in this line of work are girls. At my clinic there are 25 girls and 2 guys. Both of our male employees are doctors and 6 of the girls are the doctors, the rest are receptionists, assistants and techs. I've worked with these girls for well over a year and just now am I starting to have difficulties. I do my best to separate professional life from personal life but recently, they've kinda bled into each other. And thats not always a good thing. Im finding myself trying harder and harder to become "friends" with these girls. I mean, at work, we all get along, we all chat and have fun and make an alright team. But i figured that maybe if we were friends that the teamwork, communication and dedication would improve. So i tried but now, it just seems to be biting me in the ass. These girls are not the best of friends and I find myself isolated becuase I tried to do the friends leap. I know, my bad. But now, the team work seems all out of whack and I find myself feeling a little jealous with how well some of the other girls get along. Like, why can't i get along with them like that? And I did all of this becuase I wanted a better team, i wanted us to become not only team members but friends who we could turn to in times of stress. And maybe thats it, thats my problem... in times of stress, they could be the ones I turn too becuase they understand the job and therefore would understand my stress. I can go home, and complain and vent to my family all night long but they dont truly understand where Im coming from or know what Im talking about. So what to do? be friends with these girls and cross that professional/personal line or dont do anything and find another way to release some of the stresses associated with work? But i gotta say, stress relief is not my primary reason for wanting to be "friends" with these girls. I mean, whats the harm in getting some friends in the biz? We all share the same passions, we all have our own pets, we all have a lot in common! So woulnd't the people you work with sort of be the best candidate for a friendship? And who knows, maybe Im saying this and feeling like this because I dont have the best of friends in my life. They are all on different chapters then I am. So theres no familiarity with them anymore... winter always brings the blues and i do my best to fight them but I cant win all the time unfortunatley and this time, i lost.