These things happen, it is not a reflection on you.

Buy a can of salmon, or a can of tuna in OIL (not water) and put some of that in a bowl and put it out. These are really smelly and should attract him.

Do you have a Have a Heart trap? Or can you borrow one? Once he starts coming around, you may not be able to catch him, you may need to trap him.

My Mandy got out, 2 years back. She hadn't a clue how to care for herself, and stayed in my back yard, eating all the food I put out for her and gazing down at me from the roof of my shed. I had to use a trap to get her in. OF course, I caught LACEY in the trap, first, lol. Took about 8 days, but at least I could see her and knew where she was.

Good Luck!