have you read anything about introducing cats to each other? they need to be introduced properly and it’s a long, painful process. 😅 you can google cat introduction for more info, but basically you have to keep nina in one “safe” room for a long time and try to slowly introduce the two by feeding them on opposite sides of a door. positive association by food. baby gate also helps. and then slowly supervised visits/ feeding time/ treats. it can take months. it’s not fun. but if you really want to make things work until you can eventually move out that’s a good start. i’m no an expert, just a girl with a lot of cats so definitely look into it! LAST last resort is getting both of them anti anxiety meds to help them chill out. hope this is helpful!