Seeking Advice/Support: Despair after Foster Period Ended

After a few years off from fostering, I just fostered a puppy for a week and am feeling really sad about giving her back to the shelter and the uncertainty around her future. I am a full-time student who had a week off from school, and wanted to contribute something positive. It is not possible for me to continue working with this puppy, but I’ve struggled with the urge to completely rearrange my life in order for her to keep staying with us.

I have a very supportive partner and group of friends, but none who foster. I would love advice on how to deal with this, particularly if you have had a lot of grief/guilt after short term fostering or worked with animals who have come from bad situations and were sent back to a shelter after fostering.

For additional context, this puppy was rescued from a hoarder, and is tied up in an ongoing legal case, so she is not up for adoption. While kept confidential by the shelter, it was easy to find the details of her case online, and while I have a strong understanding of mental illness and am extremely empathetic, my anger at the woman who hoarded and abuses her animals has only gotten stronger. This is my first day without her and I just wanted advice about how to not feel horrible.