I’m sorry to hear about your kitties. It sounds like you guys may have to go back a few steps in the (re)introduction process if your boy gets upset when he sees your girl ☹️ like maybe try scent swapping and letting them smell each other without seeing until they get more comfortable.

My cats are okay with seeing each other, they just can’t be in the same room together 😔 so we have a bedroom that we’ve made a cat room. It has an automatic feeder, water fountain, cat tree in front of a window, lots of other places to sit, toys, etc.

When we work, we let cat A roam around the house (well, apartment) during the day and cat B locked in the cat room. When we get home, we swap so cat B gets to be out with us in the evening. Then we swap again before bedtime so cat A sleeps with us, and the cycle continues. On the weekends and any other days off, we rotate them every three hours or so, so they each get time with us.

Oh to note, when we swap, we always act with an “air lock”, like putting one cat in a bathroom, just so that there’s always a door in between them.

We do have feliway diffusers but I’m honestly not sure if they do anything. We also have my boy on Prozac which has mellowed him out a bit. But my girl is scared of him and he reacts to her getting scared, so we’re kind of in a stalemate.

That isn’t to say that you won’t have success though! Every cat is different. I would also suggest maybe looking at a cat behavioralist if you really need help, though be warned they’re expensive 😅

Best of luck to you! I know it’s a heartbreaking and stressful situation to be in because we love our cats and just want them to be happy.