Subtle abuse related to controlling my emotions related to grief

[Oscen]

My M has always been weirdly controlling over how emotions can be expressed and displayed.
My reactions to deaths in the family have been constrained and unprocessed because of it.

When my grandfather died while I was in my teens in another country. I didn't really have any feelings about him dying - without the body it felt unreal.
At the memorial service, I remember my M choosing to place me at the front of the church with my younger sister and saying something like "we'll have two up at the front looking sad, so everyone can feel better".
I hated the idea that my grief should be a display for others to feed off and benefit from; and to make the family look "good", and made sure I didn't shed a tear, not that I felt like it anyway.

A few yours ago, my partner's mother sadly died from complications with cancer. The way it happened was very unexpected and sudden.
It was the first time in my life I've interacted with death and grief in a normal way - we got the phone call, we cried, we went to the funeral, and so on.
It was devastating, but a healthy reaction to an awful reality.

M reacted in weird ways. I've spoken to her about it twice with the same result - she ended up trying to control what I say and how I feel.

First, she was the one who brought it up both times. Both times, I felt flattered that she cared and was interested in hearing my thoughts and feelings.
Then I started talking about it, naively opening up and saying how upset I was for bf's family because it was so unexpected, etc.
Then both times, she's gone beyond her tolerance level of having me speak about something unrelated to her, and she's snapped at me.
She ends up saying that that's "normal" with cancer; people die; implying I should "get over it", etc.
Trying to make out like my emotional actions are wrong and coming from a place of ignorance to make me feel inferior.

I hate that she can take the death of my bf's mother, who my bf cared about enormously, and twist it and make me off-balance and worrying about her reaction.
Why can't she just be a normal person, a normal mother, and support me, so that I can support my partner?
I also hate that I was fooled by her both times, and opened up. It makes me feel had, like I've lost a competition or a game. Her little game, with rules that she changes.

What kills me is, she brought it up. She's obviously not that annoyed by me talking about something she has no true interest in; she likes being able to slap me down.
She gets me opening up, milks it, then gets off the hurt and confusion I display.
No more, I'm wise to her sh*tty little tricks now. No more attempts to improve our relationship by trying to make it normal and share my thoughts and feelings.

She's not normal. My responsibility is to protect myself. 100% grey rock from now on.

[Three Roses]

She's not normal. My responsibility is to protect myself. 100% grey rock from now on.

Good for you! It's sometimes a sad, difficult thing when we have to limit contact or connection, but I applaud you for the strength to do so.