I think the local SPCA will be where you end up going, knowing you did your best and move on with your life with no shame. Sorry that this is not more what you and we all would like to hear.
That’s probably the best alternative. I remember a whole bunch of flak about the American Society for the Prevention of Cruelty to Animals a few years ago. They were NOT connected with local SPCAs. Most of their marketing was for fundraising, IIRC and not much at all done for animals in general. They’ve done some online web rehabilitation from what I can see but I still wouldn’t recommend the ASPCA. Go local SPCA and ASK them what they do, first.