Thanks for the responses
Charlie is/will be 8/9 this year. (I don't know his exact birthday)
I have had him atleast 7 years and he was around 1-2 years old when we got him. I believe Winston was also around the same age, I had him when he was an adult from a rescue and I had him for 6 years.
I have already removed the mirror I did so in an attempt to make him eat rather than dropping the food for it (I have never in all my years witness a budgie do this) and to encourage him to communicate with the other birds but he isn't bothered :|
I take Charlie around the house with me, unless I am going outside, cooking or bathing etc. He has an entire room for himself and he just uses the cage as a pit stop that he can freely go in and out of and get food and water. He actually seems to be more content in my bedroom, yesterday I tried him in my bedroom and he ran up to my makeup mirror and pecked it a few times (he always did this when he was younger) this is the most action I have seen from him since last week.
I have cleared some desk space and I might move his cage into my bedroom until he feels a bit better, I will see how he goes.
I will try the millet and gaurdian angel now, if this doesn't work I could try hand feeding him. I will consult the vet on the best way to do this. (I have never had to do it) and I am trying to stress him out as little as possible.
I have a tablet that I let play random YouTube playlists when I am not here.
And I agree about the other birds, I think it may have been too much too soon for Charlie.
I might move Charlie to my bedroom, this way he knows I am not leaving him and see how he gets on.