Hi Retired2017,
Welcome to the BPD Family

I'm so sorry to hear about your granddaughter, that is a terrible and painful loss.
It sounds like your daughter has had both setbacks (addictions) and made progress (getting her addictions under control, holding a good paying job... .). I'm sorry to hear that your anxiety level is so high, has something happened recently that has triggered your anxiety level to go up?
It sounds like you could use some self care, it's really important that you take care of yourself, you won't be able to care for anyone if you make yourself ill and exhausted. Maybe think of something you can do everyday even for a few minutes that is just for you and takes your focus off your daughter for a little while. I'm a quilter, I start sewing and my mind comes more into the present, not ruminating on past and not worried about the future but I'm just in the present moment focused on the task at hand. Can you think of something that puts you in that place? For your physical health and help with your mood some exercise would be good and no you don't have to go to the gym and pump iron! Maybe just a walk around the block to start. Get some sun and get those endorphins going, I know you will feel better.
... .always borrowing money from me even though she makes great money for a single person.
I told her I was not going to enable her anymore when it comes to lending her money for things I feel she is able and can do for herself... .
I think this is an excellent boundary, you are absolutely right that she can do this at 47 with a good paying job, she sure can.

Boundaries aren't to punish someone else they are to protect ourselves and at 67 and retired I'm sure your money isn't growing on trees and you do need to take care of yourself here (this isn't selfishness it is self-care!).
... .and she comes back with "isn't that what Families are for"?
Above is what we call FOG (Fear, Obligation, Guilt) or emotional blackmail. See it for what it is and act accordingly... .you see the Obligation and Guilt in the above statement. No families are not endless supplies of money as adults we are expected take care of our own responsibilities.
A link to more on FOG... .
https://bpdfamily.com/message_board/index.php?topic=82926.0She accuses me of being too critical, that she doesn't know what I want from her, that nothing she does is good enough for me, etc and then I find myself backpedaling and feeling guilty. Is this manipulation on her part, or can she really not see what I am saying? I am so confused.
To people with BPD feelings can often equal facts to them. You most likely aren't being too critical but she
feels like you are. This is where validation could be helpful. Validate her feelings (this doesn't not mean validate bad behavior and this doesn't mean validating the invalid).
More information on Validation... .
https://bpdfamily.com/message_board/index.php?topic=81442.0https://bpdfamily.com/message_board/index.php?topic=124001.0I'm really glad you decided to join us and jump in with your first post

There is a lot of support, information and tools to be found here and a group of really great people that "get it".
Take Care,
Panda39