Corky dog not eating & wanting to get up on things but cannot & very needy?

Sounds like you have an old corky, is that correct?

Corky the corgi is 6 years I think

Dogs in pain won't eat.

Dogs having a hard time doing things they once could, are signs of pain.

Corgi's... with their long backs, are predisposed to back problems such as Intervertebral disk disease. It can make them lose the feeling of deep pain. It can cause them to lose use of their legs if severe enough..

You need to take your dog to the vet.