Devastated and scared

Hello - I am in a state of shock right now. I had to put my beloved cat down around 2 am this morning. He was having neurological symptoms and just not okay. This is now my second cat in over a few years I’ve lost to FIP - I first lost one of my twin boys around 6 months old. Turkey my boy who I lost today is who healed my boy who lost his brother. With that being said the two cats who have passed from FIP never met or shared any spaces or anything like that. What can I do to keep my remaining cat safe and healthy? I’ve removed all litter boxes and replaced them.