Need some advice with my 3 month old

I noticed my 3 month old rat, porcupine, puffed up and hunched over last night. I thought maybe he was just sleepy but upon further examination I noticed his breathing was labored and his eyes were watery and he seemed to be moving slower than normal. When i took him out of the cage he would start acting normal for a little bit, but eventually he would go back to the same behavior. I’m really scared and the vet doesn’t open for another hour, i’m not even sure if i can get an appointment today as there aren’t many exotic vets that i trust know what they’re doing, and i’m sadly not financially stable at the moment so it bringing him in at all is extremely stressful but of course i’m willing to do whatever it takes to make sure he is okay. I brought him into the bathroom with steam and have a humidifier going now. I need other advice - how do i help his labored breathing? is he going to die? please help