If it happens again I'd try to say something like, please, it's still a heartbreaking discussion topic for me, can I politely request people not to ask me how I am regarding this, any further.Ok .. hear me out . I took time off after my mum died and I can finally talk about her death without crying. Some colleagues won't just stop at Hi ,how are you . They keep going on and on to the point where I burst into tears and it seems they enjoy that element of making me sad so they can feel special by comforting me .
They aren't even close colleagues . A friend observed this recently & after the other person had left said they were on the verge of telling them to duck off because it was blatant goading.
Don't get me wrong, it's nice for people to ask how you are but that's where it should stop .
Or is there a manager you can have a quick word with who can send an email or speak to the colleagues quietly and say look, don't bring up this on conversation please. This happened at my old job where a lady was so excited about marrying her long distance fiancee abroad, we all heard about all the details of her wedding plans, hobeymoon location, etc. She took a month off to go get married and honeymoon. When she came back she was absolutely in pieces and an email went round to us all saying she'd been jilted and please don't mention it or her time away.
It's a difficult one but worth considering if people keep prodding you. And to be honest I was grateful to be told not to ask, so that I wouldn't accidentally upset her.