I think I've got a sick budgie on my hands. Little Loki. His friend died not that long ago, so I think he may be stressed/depressed as well.
Unfortunately, I've been at University, and my parents have been caring for my birds. Sonic passed away while I was gone, and before I'd left I'd taken her to the vets and gave her antibiotics. We kept her inside for a few weeks and she was scarily snuggly, and it was out of character for her; she'd never been one that liked being handled, and here she was, climbing up into my hand and snuggling in, and then not wanting to get off. She appeared to get better though, so we let her back out with the others, but it was too late. She passed away two months later.
Loki is displaying similar behaviour, and I'm concerned that he may he heading downhill. A visit to the vets is going to happen. But I'm wondering if it's common for birds to be like this when they're quite ill?
I am so sorry your experiencing so much stress and problems.
I agree definitely take him to the vet as soon as possible.
It is normal behaviour they become quite docile and need to be kept extra warm. Keep him near by and let him know you are there with him.