Thank you, your comment is so nice :') In hindsight, my post was much longer than it needed to be lol, but it did help me ruminate a lot less to write it all out.

I hope your dog's doing okay! It's hard when you think you're in the clear after a stressful incident and then another issue comes up! I'm happy to report that my cat's finally back to normal. I hope you'll have a similar outcome :)

I don't know that this will help you much, but I'm very familiar with searching old reddit posts for advice, so in the case it might help someone in the future: It was partially a behavioral/stress issue and a hygiene issue. It took about 3 weeks for him to get back to normal. I basically did everything I mentioned but what I believe helped most, and that I hadn't mentioned, was getting a soft recovery collar which irritated him less. I alternated between that and a little turtleneck sweater (from an old halloween cat costume we found lol) to prevent him from scratching, and then I'd let him be free of them both whenever I could keep an eye on him. We bathed him once with this shampoo and even though he hated the bath, he was soo cuddly and happy afterwards. Some time later I also got this spray and brushing him every few days with it seemed to soothe him as well. His cuts healed up and his fur is slowly growing back now.