Beth, I'm so sorry. Herald was a lucky kittie to have such a loving mother.
may you find comfort now in your happy memories of him. You did the right thing, of course.
I am actually going through the same thing with my kittie Pearl right now, who has been hanging on for dear life for the past two months, always faking us out each time and making 'one last stand' after another.
I am bringing her to the vet tomorrow, and depending on what the vet says about what awful new thing is going on in her poor little mouth now (on top of everything else she's struggling with), we may have to go home in an empty car, just like you had to do today today.
I would have brought her today, but we had a 22" snow blizzard and everything was simply closed and snowed in.

I feel for you- it's so very hard losing our 'babies', isn't it? But we just have to do the right thing for them if they are suffering.