Feeling Low

I've had better days.
Got the usual three buses and arrived at Betty's door in Santa Barbara at the usual 11:30. She told me she had been sent a new debit card, but she called and they said they didn't have the number. I knew there must have been some mix-up, so suggested we go right to her bank, which is right at her corner. We did and the person there activated the card or whatever. I'm pretty sure she had just given them the wrong number.
We went from there to lunch at Lure. Betty had shown me a check from an insurance company, which she was carrying around. She said Carolyn had deposited it, but I was sure she hadn't, because there it was. I told Betty she should deposit it, we went back to the bank and she did, but  I found out later that Carolyn had, indeed, deposited it from her phone; I had forgotten you could do that. Carolyn called the bank and explained what happened, then we walked back and got the check, which hadn't yet been posted, so no harm done.
Except that I felt terrible and still do. I had tried to help and, instead, had added to Carolyn's never-ending chores for her mother. I still feel bad about it. Called Ellen on the way home and felt a little better, but not by much.
I know I tend to dwell on my failings and maybe blow them out of proportion, but this got to me. Of course, it's also terribly demoralizing to see my sister's decline.
Didn't get home until dark and had a sketchy dinner. I had difficulty sleeping last night and tossed and turned for what seemed like hours, brooding over things, I guess. Today, I just want to lie low until I get out of this dark mood.