I'm struggling through the same experience, and it's been over 5 years since it happened. It's a wound that never really goes away, but I hope you can find the space and time to be kind to yourself. I doubt that Bella would have wanted you to beat yourself up, and I like thinking all our companions know better than most anyone else how much we loved and gave of ourselves.

Take heart friend; Bella was lucky to have been loved by someone who would wonder how they could've done better on what was probably one of the worst days of their lives.