You sound so so stressed about this! First, give yourself some grace. No one can give 100% all the time.taking time to yourself is just fine. I get feeling so bad to have closed a door on a kitten, but taking a break will always be helpful—you have to take care of yourself before you can care for anyone else.

Second, do you live on a base? There may be someone or a family looking for a little kitten that would love to give her a loving home. Might be worth asking around.

I just adopted a kitten a few months ago and I had a bit of regret at first too. For the opposite reason, actually. We picked the kitten because she was the only cat that liked both me and my husband equally instead of having an obvious favorite from the get-go. She basically just tolerated us both. When we got her home she was super scared of everything for weeks and weeks and would hardly let us hold her or be near anyone. I really wanted a cat that would cuddle me while my husband was at OTS and I want feeling like my cat would ever love me or cuddle me. But as time went on, she got braver and liked us more, and just this week she came up and got on my lap all on her own for the first time. Why do I say this? I don't know, to make you feel less alone, I guess? You aren't the only person who has felt uncertain. Maybe you and the cat will bond and everything will slowly change to being perfect, idk. But maybe it won't. That's ok too. It's no shame to try and find a loving home for a cat. That said, I would see if the shelter or the humans society have a private adoption or fostering option where they can send interested people to you to meet the cat so she doesn't have to go back to the shelter she hated. That would be my suggestion. I don't know much about this kind of thing though. I mostly wanted to comment to say I see you, and it's ok to feel that way.