Where are you ?!?!

My dad isn’t home yet.. and it’s 11.30. I don’t know if I should call my grandmother to see if she knows where he is. He has a gambling addiction, so sometimes he’ll stay out pretty late, but I don’t think he’s even been home from work yet at all. He usually feeds the cat when he gets home cause she’ll have eaten all her food, but when I got home at 11, there was no food in her bowl. And I left at 5 to 6, before he usually gets home from work, so I have no clue if he actually came home or not. No lights were on, there doesn’t seem to be any extra dishes, which mean he hasn’t eaten if he’s come home. And he’s working in the morning, so he should be home by now, he’s usually in bed watching TV. . .
He’s a gambler, so he sucks at taking care of money, paying the bills on time. The landlord came by around 4-5 ish, for my dad, but I just told him he wasn’t home, cause he wasn’t. People can do stupid things when it comes to money, and I’m pretty sure that’s why the landlord was here. And  he really creeps the fuck outta me.
My dad also recently had a gull bladder stone attack, so if that’s happened again, he’s back in emergency.. I really don’t know what to do, for all I know, he’s out screwing this chick he has a thing for at work, and good for him if he is. But I’m really worried. And maybe I’m just being paranoid but I’m scared something’s happened to him.