NTA

For reasons lots of people above are mentioning.

As for your mother, does she have a history of exploding like that on you, about a lot of topics? Or just this one topic? Also: does she frequently make you feel bad and make you question yourself?

If it's just this one topic alone, then don't take it personally. She shouldn't have reacted to you that way... but she's still stricken with extreme lingering grief over the loss of a child.

If however she frequently makes you doubt yourself, and makes you feel bad after you two spend time together... then hate to say it... but the less time you spend with her the better.

If that's the case, then she'll guilt you out for not spending more time with her in the future, but she doesn't own you, and you get to decide how to spend your time in life, because it's your life. And life is too short to spend with people who make us feel bad all the time.