My situation was a little different. I saught counseling during a rough patch in my life, but I was still very active in my sorority. In fact, it was the highlight of that semester; what kept me positive I guess.
However, if sisters are the issue, perhaps it may be better to take a small leave. I don't know the national processes with your house, but in our's we can take leaves of absense for a semester and come back the next without question.
Your primary concern should be yourself. If you are having trouble, that should be your focus. I'm sure your sisters will understand. And there is no shame in counseling. I did for a couple weeks and it was good to just talk to someone who didn't know me and couldn't judge me either way. And I went through my school and didn't pay a dime (out of pocket I mean...).
I say go for it. And feel free to PM me if you need support.
Sending you prayers and happy thoughts.