Hello Stoman:
You wrote about your daughter "just been diagnosed and on new medication." Has she been diagnosed with BPD?
Having to deal with just one child with autism is difficult but to have two is unthinkable! I am so sorry this has happened in your daughter's family. It is good to read that "she has a lovely partner who is supportive." Still... .so, so difficult! I certainly hope they have found a support system in their community.
Now, with all that said, sounds like you are being used as an outlet for your daughter's frustrations. It is easier said than done to see past her anger, though, isn't it? It will definitely be to your advantage (and hers) if you keep working on the skills of communicating with her and defusing situations.
As you do this, you have to keep YOU in mind. To the right
under "Tools" you will see "Communicate Boundaries and Limits." You can see ways of protecting yourself.
I so wish you well, Stoman. I, too, have felt my daughter's wrath and so many times my skin has not been thick enough to weather the blows. It does give me comfort in knowing I am not alone... .nor are you. Glad to have you with us!