Your story breaks my heart. For you. I am so sorry for your loss. I know how these little ones can wrap themselves around your heart. We have been in emergency a couple of times for various things. I cried all the way home one of the days I had to leave Copper overnight. I thought we were going to lose him and I blamed myself although I have no idea what he ate that caused the symptoms he had. We picked him up the next day. He was weak and tired but ok, thankfully. I cried all the way home in relief. It could have easily gone the other way.
It may be too soon, but please consider another companion. Forgive yourself. I will pray for your hurting heart.