Oxygen chamber for rabbit?

My rabbit got attacked by my dog. Ill make sure she never gets in the rabbit's pen again. Soon after, she started wheezing, then her eyes became watery and she bled from her nose. This was on a saturday and the vet wasn't open on weekends. On monday (yesterday) I took her to the vet who put her on some oxygen, gave her 0.6 cc of antibiotics, and some fluids. I took some antibiotics home to give her every 12 hours. The vet recommended that I rent an oxygen tank and mask at a medical supply place, and most of the ones I call are not respitory licensed. The ones that are just have a concentrator that I can rent for a week. After calling the pet hospital back I spoke to another vet who said that he doubts I can get an oxygen tank that will last long enough (atleast 24 hours) and that I'd need to put her in an enclosed box (not completely airtight) and this is somehow supposed to give her more oxygen than being outside, or in a well ventilated room? Is giving her Nyquil a bad idea?