Grieving loss

I was in a long-term relationship and I became the caregiver. They had a lot of animals and various health conditions. I adapted because I loved them. They were able to live a happier life because I showed them that they deserve it. There were better relationships with family and they were just bubbly. Things were great, but there was an accident involving an animal that resulted in the passing. The guilt and shame I feel regarding the situation haunt me every day. I took accountability for my actions, but it wasn't enough. I respect that and care deeply. I know I need to forgive myself for what I did and the trauma I caused. It's just so hard because I love them and still care. How can I manage these emotions?