Desperate about the lost cat

It's a difficult situation. Someone who was supposed to temporarily take care of our cat made a serious mistake, and he got out. I haven't been able to forgive them since, but at the same time, I feel even more anger towards myself. Why can't I find him? He was so unusually cuddly before disappearing. What happened? It's been three days.

He belongs to my family whom I am visiting right now. I'm the only one actively looking - everyone else gave up or hopes he would return on his own. Unfortunately, I have to return home in several days and won't be able to help anymore.

Asking online, checking the yard and surrounding streets multiple times a day, even entering abandoned places. We live in the rural area - there are simply too many yards, basements and forested areas for him to hide. Someone spotted him in a specific area but I found out too late. Placing food and his familiar stuff outside has attracted stray cats but not him. I hoped he would recognise and follow my scent back, but it hasn't happened yet.

He's so shy and escaped during the coldest days of the entire month. The fireworks night is coming and so is my departure date. I am so desperate and angry. My mind keeps blaming everyone, but it just hides my own regrets. He doesn't deserve this, definitely not during the holidays. I can't stop thinking about him being alone and scared. What can I even do? How to stop the resentment?

Please come home.