I'm sorry about your bunny. Not eating, drinking or pooping like normal is a major warning sign - just in case you intend to take another rabbit, you should know for next time that a rabbit that doesn't eat much should be brought to the vet as soon a possible (it's a matter of hours, not days). It's generally more of an effect than a cause (even if slow or, worse, stopped bowel movements will cause death after a few days - when the guts aren't working like they should, bacteria multiplies inside the guts which causes an infection and kills the rabbit). It's often caused by pain. From what you described, my money is on a tooth problem - a malocclusion would explain the pus on the eye and would make it hard for the bunny to eat. The cause of the malocclusion might be several things, including your rabbit not eating enough hay (I'm not saying it's your fault - some rabbits don't eat as much hay as they should). Of course, it might also have been an infection. It's impossible to be sure without an autopsy. When raising rabbits, we learn to be really paranoid of every little change in their attitude. Rabbits are very fragile and, if a number of things can be cured if taken early, you can't afford to delay a visit to the vet (even if it's not always simple to just drop everything to go :/). I saved one of my rabbits last Christmas, barging at the vet on the 23th of December asking for an x-ray and cancelling my trip to my parents because Aki was kinda hunched and refused a piece of carrot. I think the vet thought I was barmy - in the end, her stomach was full, her gut movement almost stopped just because the latest hay bag didn't contain as much 'hard' hay wisps as usual. If I had waited, she would have died. Rabbits are just stressful that way. Owning them, you feel like you spend your time scrutinizing them and dreading to find anything amiss (they are lucky they're that cute, because I sometimes wonder why I do this to myself).