I am very hurt, when I left my job after 12 years I didn't even get a card.

[HelenFitzroy]

I have worked in a very high stress, professional NHS job for 12 years. I am a hard worker and have always taken my job seriously. Earlier this year my younger sister unexpectedly died (aged 27) I was off for several months due to the bereavement. My work sent flowers after her death but after 4 weeks my manager was keen for me to return to work due to short staffing.
As I was unable to walk round Tesco without crying and in the weeks after her death my hair began to fall out! So I didn't go back to work at that time.
While on leave I reflected on my life and job and decided to move to a different post within the same field.
After leaving my manager didn't call me to confirm a leaving date or to speak to me before I left. I didn't expect a big present or anything like that but I didn't even get a "sorry your leaving" or "good luck" card.

I know its silly but I really do feel hurt by this.

Am I unreasonable as I basically didn't go back to my old job after the death?

Good grief, some people wear their top notch sickness record like a badge of honour. This is what is wrong with society…valid, genuine reasons to take advantage of sick leave are questioned and judged. We all handle grief differently.
Be proud of yourself, you valued yourself enough to put yourself first. That’s all that matters.
Your work colleagues are not your family or real friends, they are the ones that matter at the end of the day.
Some managers have no compassion for their staff and just think about how much someone off impacts them instead of looking at the bigger picture.
Good luck in your new role, you deserve better.