Please help me figure this out

How is it that my biggest fear was losing my dog, and I ended up losing him after that fear got worse and while he was still so young? I obsessed over keeping him safe and taking care of him yet I didn’t protect him from whatever led to sepsis. I limited who I left him alone with, what I left in his reach, what he ate, how long he was outside. I rarely let him out of my sight and would watch him on a camera or leave him with only certain people. I can’t get past the fact that my worst nightmare came to life. I don’t understand how I’m here typing this. It doesn’t seem possible. I just want to wake up