Help needed with very sick bunny

Hi

I have 4 rabbits all Rex
I have a terrible problem at the moment which I need some advice on.
One of my Rabbits is really sick at the moment he has pneumonia.
He has been on 2 lots of antibiotics, and he is now on his 2nd lot of penacilin.
The vet x-rayed him on Fri and confirmed he had pneumonia. He is still breathing really heavily nothing seems to be working. He has lost over half his body weight.
I am feeding him 3 times a day on everything from Excel, to Greens, and Carrots, and even baby food which the vet advised me on, he is still eating really well. He really loves his food still.
He is normally an outdoor Rabbit, he lives with another Rabbit, they in they are like soul mates.
Since he has been ill for a month now, he has been indoors in my spare room, with my other rabbit who he lives with.
So I can keep an eye on him. Is this a good idea, or should he be outside where he is use to being.
He is going to the vets everyday for his penacilin injection that must be stressing him out, being put into a carrier and being put in a car.
I don't know what to do for the best. What would you guys do. I am in a awful state I am worried sick about him. He doesn't seem to be getting any better, or any worse. PLEASE HELP.

Keeping him inside is the right thing to do at the moment. I found an old thread for you: http://forums.rabbitrehome.org.uk/showthread.php?t=202758&highlight=pneumonia Please take a look at the medication mentioned and discuss it with your vet.
Sending a lot of vibes for your baby xxx

Im really sorry to hear about your poor little bunny. It seems you are doing the right thing. Sending him lots of vibes xx

Won't the vet allow you to take say a weeks worth of medication at a time so you can administer it at home? Daily trips do seem a bit uneccesary