You didn't do the "wrong" thing; you did what you thought was best for you, at the time! That is different from what your husband might have done but your husband is not you. "Wrong" is often an unhelpful judgment rather than something we can use; although, your husband's using it did get you to post here, and that's good :-)

I have the exact same girlfriend :-) from childhood; we were inseparable and I moved away in 4th grade. When I moved back in 11th grade (after going to the same summer camp she had been going to the summer before 11th and being blown off by her there) we got together once and I tried to talk about our early times/memories and she said she did not remember them. I believed her! She acted like she didn't.

Lots of people literally don't remember and some people don't want to remember or even try to remember. None of those scenarios is "wrong" anymore than remembering is right/wrong.

I think it was okay that you wrote her a note; it was about "You" and who you are and telling her you wish she'd helped you, etc. is not wrong and she can keep not responding to you, not wanting to remain in contact with you; that's her perogative. Friendships can/do end just like any other relationship and they can be mutually ended or one-sided, etc.

But I wouldn't worry about what you did/said to your friend on Facebook. It sounds very legit and about you and your concerns and that's always okay to talk about! However, the other person doesn't have to respond and that's okay too. However, if she does not respond, then I wouldn't continue to write her as you've had your say, you said it well (I believe :-) and continuance would be imposing on the other at this point if they don't wish to continue the friendship with you.