Hi Kayleigh
I just wanted to welcome you to TP, and to tell you not to be frightened off by the preceeding posts. They were not aimed at you, though I'm sure you'll heed the advice given by Bruce.
As one who has been taken in by a 'false friend', I can say that the warning is justified, although it is rare for that to happen on TP. Most of us are just wanting to help and be helped.
Anyway, to get back to your original post, I agree with Jennifer that it sounds like Lewy Body dementia.
Is your gran in a home licensed for dementia care (sometimes called EMI)? If so they should be able to manage her outbursts, and have staff to cope.
If she is in an ordinary nursing home, you may find that they say they cannot cope, and you will be asked to find a more suitable home.
In this case, your gran's social worker should help, and it would be a good idea to ring them to find out what they suggest.
Good luck, and let us know how you get on.