New kitten advice

Looking for some advice. I have a cat (6y female) and I have recently got a new kitten (5 month male). My resident cat has struggled with the new kitten only coming in the house to eat and then leaving again. They only have supervised interactions but my resident cat growls and tries to swat the kitten. The aggression remains after the kitten is out of site and towards me. The kitten has settled in fine but the cat is hardly in the house, when she is she seems stressed and aggressive. I’m scared they’ll never get along or my resident cat will become more stressed and aggressive.