Goodbye to Group Therapy?

I'm having a wee bit of a condundrum, so I thought I'd toss this out to you Blogxygeners and see what you think.  All opinions and thoughts are welcome!

So, I've been going to group therapy for a little over two years now; I know that I've mentioned it a time or two on my blog.  The group is led by my therapist and it is an eating disorder support group.  Group therapy has been a huge rollercoaster for me.  At first, I hated it.  LOATHED IT.  I dreaded group every week, and I mostly only went because my T made it a requirement that I go, because she thought it was really important I learn to open up and work on my social skillzzz.  Fair enough, so I went.  And then, slowly, group got easier for me.  I opened up more and participated in group and started to develop friendships with some of the other members, and I still love them to death, and some of them I'm still very good friends with.  During this time I really started to emerge as a group leader.  I looked forward to group, and I always felt really great afterward.

And then something started to happen, oh, maybe 6ish months ago.  I started to regress in my group experience - I started to get really quiet again, and didn't participate much.  I felt really anxious in group, and I usually left feeling really crappy.  I don't feel like I've gotten much out of group for quite awhile now.  I go because I know I should and because I committed to it, but I could be the freaking doorknob in group, for all I add to it.  I'm there, hey, you can look at me jiggling my foot a million miles a minute and chewing my nails apart, but that's about all I'm good for.

So for the past 2 months or so, I've gotten really serious about questioning if group is something that I should continue doing.  And I've been torn.  So I finally worked up the courage to talk to my T about it, and I told her basically everything that I've said so far in this post - that group used to be great for me, but that it doesn't feel that way anymore, (Why though?  I don't know!)  and I usually feel worse afterward, and what should I do?  And this is more or less what she said:
She believes that group can still be helpful for me, but only if I work really hard at it.  She says that with how long I've been in group, she expects me to be a group leader, and speak up more and participate more.  She said that she still sees me, in my "regular" life as someone who is more or less a doormat, and who doesn't usually speak my mind, and sometimes to my detriment.  She still thinks group therapy could be helpful if I was willing to be assertive and speak up in group, because that would help teach me and give me practice to do that in my real life.  But, if I'm not willing to do that in group, then she agrees with me that group is basically not helpful for me anymore, and I should be done.  She is completely leaving the decision in my hands.

And, I don't know what to do.  The bigger part of me wants to quit and just brush my hands off and be done with it.  But...if I do that...am I running away?  Am I  not taking an opportunity to learn more about myself and really grow and change some things about my day-to-day life that I don't really like?  (I mean who likes being a doormat?)  Or should I just call it quits because 2 years is a long time to be in a group, and think that I will learn to talk more and open  up more and be assertive in a different setting, maybe with individual therapy? 

I don't want to squander this potential opportunity to change and grow, because the truth is, I really do wish that I was more assertive and more open.  I'm a pretty quiet and withdrawn person, and sometimes I wish I could get out of my isolation and speak up, especially because I get walked all over all the time.  But...if I haven't yet learned to do that yet with 2 years of group, maybe I won't ever learn.  I don't know?

I'm honestly so confused.  When I talked with my T about this earlier today, I told her I was just going to think about it awhile before I made any decisions.  And I feel so stuck.  Breezy has  no idea what to do.

Addendum: I was just about to publish this post, when Brandon called.  I talked to him about all this, and he thinks I should continue group with this whole trying to be a group leader thing and see how it works out.  I'm inclined to listen to him, but I still want all of your opinions!

PS - the photo of Miss M and I has nothing to do with the post, obviously.  Just thought it was cute.  :)