You know, I sat here for a long time thinking about this. This is HARD!!!
Did your Aunt specifically ask you to take in her cat? Maybe she doesn't expect you to bring this burden on yourself. If so, then get in touch with as many rescue organizatiions as you can. They know how to tame the untamable and somewhere there MUST be room for one more kitty. That way there will be no guilt, you did your part, as most of these places are no-kill and WILL find it the proper home, and you can keep your beloved orange kitten.

.