I completely understand the superstitious aspect of this post. So many times I have said "well this is just God's way of telling me not to do this". Sometimes I listen to my thoughts sometimes I don't. I think that there really are times when it is something warning us, but in this case I think it was good that you decided to post it.
I don't think that your post is doing anything to demean your mother. She was suffering from an illness, and yet still seemed to want to keep you and your brother safe. As long as it didn't cause you to get addicted to sleeping pills you're doing good, because that is an effect from it.
I don't have much more to add, other than I understand that it would be upsetting. I have flashbacks and things from my past sometimes and it causes me huge panic and anxiety when I do, so I understand what you're going through in a sense.
Just want you to know I am reading, listening, and hoping things get better for you.