Adult brat

[alwaysadulting]

I have an adult daughter 31 and 2 grandchildren. I have had many difficulties over the past 13 years with my daughter. I have done everything (I feel) possible from encouraging, letter writing to tell her how proud I am of her to helping her in every aspect with her children, life and financial if I could. She met a man 6 years ago and was the happiest I'd ever seen. They married and had a son and he was a wonderful step parent to my granddaughter.
Fast forward. The father of the oldest grandchild was killed in a car accident about 7 months ago. Again I supported her every way I knew how. At first we thought she was just grieving and going through the stages of grief. I took her and my granddaughter on a bonding mini overnight vacation and realised something was seriously wrong. It turns out she has been diagnosed as bipolar ( which explains all my difficulties through the years with her) it is to a point that she has basically disrespected me in every way possible. The nastiest text messages about how much she hates me to her very core, lies to my family about me and how I've never been there for her (She is my only child and I lived for her) I feel she is using her diagnosis to hate and disrespect me to a level of me never wanting her in my life again. I'm sure some of it is due to bipolar disorder but I can't get past it.
Please help any advise is welcome.

She has a mental illness. Is she getting appropriate treatment? Obviously you don't have to accept abuse and it's up to you if you want to remain in contact but it's interesting that you've leapt to the conclusion that she's using her diagnosis as an excuse. That would suggest you possibly have some unhelpful behaviours yourself.

Thank you and yes she is seeing a 2 dr and is medicated. Atleast she was in October. I thought at first maybe I wasn't there enough or was giving the wrong kind of support but when I reassessed I don't believe that is the case. I'm just at a loss and am very sad. She is my only child.

How horrible. Let her get her diagnosis and when she starts to get better look at your relationship again. Do not be an enabler

That's not easy for you at all, but I think you need to see it as symptomatic of her illness and lose the terms like 'brat'. The death of her ex could have triggered an episode, I think stress can make it worse.

If I were you, I'd learn more about the condition and maybe try to talk to some other parents who have been through what you're going through. Hour daughter might have been very difficult to deal with but it sounds like she's had a terrible time too.

Thank you for your input. I have done everything you have suggested and it has turned sour. I've also talked to other people who are familiar w/biplar. Almost pure hatred for me on her part. The death of her ex defiantly brought an the most worst episode. In the past the pregnancy and then birth of her son also brought one on and also a medical issue after that.
I have had zero contact with her except her nasty messages to me in which my replies are simple. Such as "ok" or "if that's how u feel". I've done my best not to engage.
It seems from the replies Ive received I should just wait it out and see what happens. Thank you to all who have commented.