I'm glad you've decided to join us! I can honestly say without doubt that the friendship AND accountability at 3FC has been the best choice I have made in my journey.
I'd like to chime in and make a suggestion. My suggestion would be to make yourself a committment to stay on plan and post here every single day UNTIL your event and at that point accept that "where your are is where you are." That way, you will have done your best, made new friends and set yourself up for posting even on the hard days. (I've found there are always a few)
My serious journey on the road to permanent weight loss began a little over a year ago, when I was set to go on a mini vacation and had to accept that I had regained 20 pounds during the winter and was in jeopardy of regaining it all. I made a committment to stay OP no matter what for 6 months. It worked, but I can say that at 6 weeks I felt fatter than I did when I started, although my clothes definitely fit better. At 6 months I felt great, and the time OP had allowed enough time for the results of my efforts to be visible to others, but more importantly, to me.
I look forward to getting to know you better!