Please help, my rat is VERY sick!?

so my rat who just turned a year recently has gotten heavy, she was a happy fat rat until just a couple days ago, she has been immobile, unresponsive, and has had no appetite. (and she get this red stuff around her eyes about every 5-10 minutes, and its really scaring me) i'm trying to feed her and give her water. she is going to the vet tomorrow, but im afraid she won't last until then because she keeps gasping for breath and im running out of ideas, please help!!!!!