As always, tyvm again for the kind and prompt responses. I realize responding on itch is probably better than trying to get a hold of you on Discord.
That said, the videos are different as you stated; they were just so similar at first that it felt like they were identical without you noting down those differences in the reply.
I'm happy to hear your health is (slowly) improving a bit with physical activity. At least in the USA there are ways to get free rides to Doctor appts and medical services so if you need something like that it may be worth looking into for your area/country.
For crediting, it may help to put a note in the description/comment when possible stating that the vocalist requests not to be credited or that you are required by the ToS of the site you use to take credit for certain tracks. I understand it is a big ask on top of everything else but it might help.
I do have a potential answer for those asking not to be credited btw. I believe it has something to do with unionized workers doing non-union work and thus they can't (legally) put their name on it or get credited for such work if it isn't union-approved work and payment. Many actors may not get enough union-approved work so they do this 'off the record' work and thus can't obtain credit. At the least I can only speak of how it is with certain professional actors and voice actors in the USA. Not sure how other countries do it.