Grant
to the forum, and damn sorry you have to be here, but glad you found us!
So sorry you're in pain though it will gradually get bettter and try using ibruprofen to keep on top of it pre-BM, using a Sitz Bath to soak, and make sure that you have soft BMs. I have not had the surgery, but from all the others on here that have I will give you a link to Davo's (one of our moderators who did have the surgery) post after his which is a very good writeup of how it went for him.
We do understand where you're at, as know what lousy pain you can get with this, so feel free to rant. Hope the post will give you a good idea of how soon it will all be over, but it does take a little time. Did you have just the 'ordinary' LIS, or do you possibly have a stitch or two there? If you don't know, ask for your medical record of the surgery (if you want it)... Anyway, here is the link to Davo's diary (and there are quite a few more under the Anal Fissure Success Stories).
my-lis-diary-march-2012-fully-healed-in-4-weeks-t4589.html