It's all good things that kitty is still eating, drinking, and using the litterbox. As hard as it is to do, live in the present with kitty. Focus on right now, and right now you have you cat and you can give her all your love and caring. I have cats too and I've had sick cats, and cats die suddenly. It's very sad but if you think about it, if all you think about i that eventually something may happen to take your cat away, you will always be very upset and fearful. Like I said, I realize this is easier said than done but I have been there myself and as I get to the point that I start feeling sad and depressed because I think that eventually my cat won't be with me anymore I try to steer my mind away from it.... almost like grounding. It's hard when your cat is ill. If you're overly concerned then absolutely take kitty in to see the vet. I hear you when you say you're concerned. Please take care of yourself so you can continue to care for and love your cat. I'll be thinking of you.