I am so sorry

You did what you could and I'm sure you would've made it work out for you. But since it was affecting Samantha, I understand your decision. You have to look out for her first.

I'm sure the rescue will find Lila a great home.

When it comes time for another dog, maybe you could volunteer to foster for that (or another) rescue. Then while you're fostering dogs, you would be able to see how Sam reacts before you make the committment of adopting. Maybe Sam would feel more comfortable with an adult or an older puppy. I know those youngins can really be little buggers sometimes. Lolly gets really annoyed with a lot of my young puppy fosters.

Please take care of yourself and don't worry yourself sick. You can follow up with the rescue and find out when she gets adopted I'm sure.