I'm so sorry you had to experience this! So scary and so confusing, I know. Dobie clearly had 8 good, love-filled years with you, and even though it's difficult to fathom right now, I hope you can see that he likely went without pain, without suffering, having only ever known love, and was near his beloved when it happened.
I know it doesn't make it feel better for you, but we're all here to listen. Grief is a process and we must go through it.