I'm sorry to hear your cats aren't getting along anymore! I recently moved in with someone who owned two cats (one female one male), both several years old, with my 10 month old kitten (female). My kitten, Quinlan, and the male cat Pete ("Cowboy") got along fabulously for the first month or so. Quinlan's turned out to be too hyper for Pete and he hates how she attacks his tail all the time. He hisses and bats at her if she harasses him or even gets too close. THE GOOD NEWS IS they are fine as long as Q-bert doesn't attack his tail or look like she's going to. They sleep together on the couch, sometimes all squished together because Quinlan has no concept of personal space. :-p So there's gotta be hope for your two loveys!

+Jess+