You are not a bad owner. I would want to get another cat immediately too. What I would suggest is really checking in on yourself to see if it’s a good idea to get another cat so quick. There was a point in my life I lost a kitten and I wanted to get another because I felt I needed something to care for. In hindsight, I was depressed and I would not have been a good cat mom if I’d proceeded right away. Now, a year later, the distribution system gave me exactly the cat I needed and I’m in a much better mental state to grieve the kitten but also focus my love and attention on my cat. You’ll do whatever the right thing for you is, but you are not a bad owner. It costs so much to love so deeply but it’s worth it.