Just thought I would chime in with a bit of "peer support" and say I can feel your pain. I got some of the highway peg mounts from Chad last week and was really excited to get them on. To do so, I needed to remove - or at least attempt to - the exhaust pipe on the right side. Well, the first nut came off without a problem, and I thought I was well on my way to having a much more comfortable long-haul bike to ride.
But then I tried to get the other nut off. And instead of being patient (and smart) when it started to resist spinning, I put more force into it, and ended up snapping it right off. So now, instead of being all stoked by getting some "nice to have" on there, I am trying to figure out what the heck to do.
Fortunately, there are several cool people on this forum who have given me a lot of great advice, and I now have a number of options I am looking at. The easiest one, and the one I am hoping works, is to simply soak the thing down with PB Blaster for 2 or 3 days and then try to coax the thing out with some Vice Grips. If that doesn't work, I am probably going to cut the 1" of stud that is sticking out off and try to retap the hole myself. And, if that goes bad, then I will have to replace the exhause manifold.
In any case, it looks like it is going to be a little while before I can ride again. Which sucks, but after reading your post, doesn't really seem all that bad! Lol. Sorry to hear about your woes, and I hope everything works out for you. Sometimes, depending on the situation, it's better to cut your losses and just move on. Whatever happens, best of luck