Ange, I'm sending lots of hugs your way. I now how it feels. I was at the end of my tether a few weeks back. We do co-sleep and DD was sleeping really well for the first 6-8 months. But then the exact same thing happened. The front teeth (top and bottom) seemed to pop out without giving her any grief, but after that she started on some horrendous sleeping patterns. Waking up every 20 minutes some nights. It drove me insane. I am ashamed to admit, some nights I lost it. I even pinched one of DHs cigarettes one night, just to have something to calm me down. I hadb't smoked since I got pregnant. I almost puked after 4 or 5 drags. Needless to say, I haven't picked up a smoke since.
I ended up just riding it out. Whenever I tried to do something to fix the problem, it failed and I just got more frustrated. So I gave up, tried to sleep with her during the day to make up for the lost nights and on the weekend ordered DH to do night duty sometimes.
She has just fallen into a much better routine in the last couple of weeks and sanity has returned t this household. We have cut out one of her daysleeps and although I don't think it was the only reason for improvement, I think it has helped. But mainly, I think she just got through this phase. No new teeth, though.

Please believe me that you're not doing anything wrong. Sounds to me like you're doing an amazing job, I know how hard it is at times. Keep up the good work and don't blame yourself. Unfortunately they just go through stages like that and there isn't much you can do about it.

All the best, hun
Sasa