My LO is exactly the same. We've had some success with the "Pantly pull off" (essentially, break the latch every 10 seconds once they've finished feeding, if they fuss give it straight back) my DS does give in evenrually as its just too much hassle keeping relatching. It can take a while though, he'll persist for 10-20 relatches! After doing it consistently every feed for a few days he's much better, he rarely breaks the latch himself, but will mostly give in to me breaking it after just one or two attempts.
Alternatively, I got fed up last week and just refused to give him the nipple back (after a night of non stop feed/cosleep on holiday). It took him an hour to stop complaining and settle himself, but there wasn't much real crying involved. Could you try that? Just break the latch and put your top back down, but continue to hold to settle her? If she's just displaying anger and frustration it hopefully won't be too hard to hear her cry, and she'll hopefully learn that the nipple is not a dummy.
Can't offer you advice but I've been in a similar position with my DS since he was about 6-7 months. He's 11 months and we still haven't solved it. I still sit holding him for his naps. It's mad, and has been worse recently. He's got me round his little finger.
It might be too late for a dummy, we tried to introduce one around 8 months and he wouldnt have it, just took it out his mouth and played with it.
However, my DH can get him to nap/sleep when I'm at work. Could it be because she knows you're the one with the boobs she makes a fuss? Will she settle better for your DP if you stay totally out the way?
As I write this he has my nipple in his mouth, he's not properly feeding but not totally asleep and if I unlatch him he'll cry!
My 9mo isn't a brilliant sleeper but got loads better around 7 months. We did some cc for naps and night which went well, and she then settled herself or fed to sleep.
We've been on holiday lots recently so her schedule has been non existent. She managed ok for a whole bit has gone backwards in self settling (expected) and as we've been staying with friend we haven't been able to let her cry. I've been feeding to sleep as a result.
Now, I find that she will latch on, feed sleepily for Ages, and then squirm, root and cry when I unlatch her. I'm going bonkers with this - last night I was holding her for 1 hour and then 45 minutes before I could put her down.
Any advice? Wait it out? (We're doing more travel so routine won't be reestablished until end October). Give her a dummy? Help!