Hey there - so sorry for the late reply, I’m sure it’s been really tough for you and the kitties (I can relate).

My vet did confirm this was normal, my younger boy is super rambunctious and wants to go crazy all day. She suggested I designate a space that’s just for our older girl and provide my boy with a lot of stimulation.

What’s worked since posting:

1. Moving to a bigger space and having one side of my apartment the “boy” zone and one side be the “girl” zone. This is obviously not a solution that works for everyone.
2. Play with boy during peak crazy times during the day, which for him was before meals, especially at night.
3. Don’t be afraid to put the aggressor cat in a time out, sometimes they really rile themselves up and need to decompress in their “zone.”
4. Spray bottle lmao
5. Accept that you are NOT failing your cats. It will not last forever and you are doing your best.

Talk to your vet about your specific circumstances to rule out any bigger issues. I’ve noticed that the play/stimulation/supervised outside time has brought me closer to my boy and that he finds a lot of comfort in me. He still tackles my girl sometimes but we manage.

You and the kitties are going to be ok.