Naked Rat/ New Owner

I got this rat a week ago from my friend after his buddy ate something wrong. It's been a week and he was doing fine the first few days. In the last three days, he's stopped really walking around at all. He keeps getting red stuff around his eyes to the point he's needing a bath daily or his eyes will get stuck. He's breathing fine, but today he won't eat and his tail has sores on them now. He's cold to the touch despite the fact that I've had him cuddle against me for an hour almost. He also keeps like twitching like he's moving his foot around or something.

I'm not sure what to do and I got exposed to covid, so my fiance who knows how to care for rats can't come to my house.