Is this grief or regret?

I decided to re-home my puppy (full bred Aussie) of 13 weeks on Monday, it was the hardest thing I’ve had to do and more people need to talk about that part of it! I’m grieving hard even though my decision to re home her was well thought out. I have two kids under 10, and work from home. trying to teach my kids to be calm so the puppy could learn to settle and be calm was exhausting. She was nipping during wake hours out of the crate and just acting crazy anytime my kids were just being kids. It wasn’t the dogs fault, it wasn’t my kids fault but it was 100% affecting my mental health. I now have wondered if we could have just stuck it out until teething phase was over, or if I was realistically in for way more work than I could handle right now. I’m waking each morning having regrets of rehoming her, is this just a normal part of the grieving I’m going through? We still have her bed, her toys, her leash, and when I see these things I tear up wondering if I did the right thing. Every time I come home I stare at the front yard remembering how my days were filled with just caring for her and taking her out every hour to potty. I can’t stop thinking about her, and wondering how she’s doing. The new owners agreed to send us updates of how she was doing and growing and while I don’t expect that.. that’s all I can think about now. I have seen a photo of her with her new owners and It makes me so sad that they “have our dog, will get to love on her now, and watch her grow and get to experience life with her” I feel like I will never get over that part and that I will always wonder “what if”. That is what gives me the feeling of regret even though I know she will be taken care of. Will I ever get through this side of it? I will always wonder if I did the right thing.