Can I get some suggestions, about writing a letter to the family of my donated liver?

As some of you know, I received a liver transplant in October 2022. My health has been up and down, but is mostly up now. I wanted to write them, when I knew I would probably live. (If that makes any sense.)

I have a specific person who will proofread it, and decide if it can be sent to the family of the organ donor. So. I’m not concerned about saying the wrong things necessarily, but I really want to express my gratitude. If I were them, I would likely take great solace from knowing that someone is alive because of their loved one.
It also occurs to me, I could be reopening a families’ wounds, simply by bringing all of this up.

I have written huge, lengthy versions. I thought about trying to keep it simple, and don’t really like that either.
What would you like to hear, from someone like me if you lost an organ donor loved one?

When I opened my eyes, after a 10 hour surgery, I immediately felt better. It was amazing. It’s fairly impossible to articulate.
Any help, would be greatly appreciated.