My cat is dying

I used to be a devout Christian and I lost my faith about a year ago. I’ve tried rationalizing and having faith but I haven’t been able to bring myself to believe for quite some time. I miss god and I miss believing. I miss it so much. My cat is dying, which you know from the title. The thought of literal nothingness for her for the rest of eternity is keeping me on the brink of a panic attack. I just want to know what made you believe or made you stay believing. How can I believe again?