As hard as it is to deal with their cages and their areas, you must.Mr. Charlie needs you more than ever now. Do what you have to do to grieve, but don't ignore the others. It's okay to cry and be sad, but it's very important to thoroughly clean the area where the bun that passed resided in and extremely important to be there for your other rabbits and Mr. Charlie who doesn't understand what's going on. You don't want to stress or upset him by ignoring him.
Be strong, you can deal. You have to for the sake of the other rabbits in your care. Perhaps you can solicit the help of a family member or friend to be with you until you get more comfortable and used to the empty cage.
Again, I'm sorry for your loss, but don't let the loss of one rabbit take away from the attention and love you have to give to the others.
-Carolyn