I rehomed one of my cats yesterday. Advice needed

I got my first cat Peanut in college. We've been through a lot together in the last 5 years, he's been by my side through it all. For the last two years, I've been trying to manage his FIC symptoms- and it had started out fine. I could afford his prescription medication and food. In the last year I've had some really tough financial problems, and it's taken a huge toll on my mental health and his comfort. I can no longer afford any of his prescriptions, and hes had 3 episodes in just a short month.

I felt I ran out of options, I don't have any family that could take him, nor any friends with the right time or resources to help his condition. So after some heavy thought, I felt all I could do was surrender him.

I turned him in as a stray, since they wouldn't take him any other way. I wrote down my number and told them if nobody picks him up and his time at the shelter comes to a close to PLEASE call me and i'll figure something out.

That was yesterday, and the grief has hit me really hard. He must be so scared and traumatized it hurts my heart so much.

How can I deal with this pain? Will they actually call me if they need to? I'm in a horrible struggle wondering if I did the right thing...