Newatthis
You have answered your question "Not sure what I've done".
You were a kind person who listened and sympathised, you gave her your time, your attention and your care.
You did nothing wrong.
Her dropping you isn't about you.
You did what you could do, you did it freely and often and you don't seem to feel used by her.
That's good.
Her dropping you isn't about you.
You realise you don't need her in your life to make your life better.
That's good.
You recognise you have a good life, with family and friends.
That's great.
For whatever reason she has stopped her contact with you it has to everything do with her and/or her husband and Nothing to do with you.
It is always sad and uncomfortable when this sort of thing happens because the person who it happens to is left with no explanation, no understanding and nothing with which to make sense of their part in anything.
Therefore, it has to be everything to do with the other person and Nothing to do with you or how you were towards her.
She may feel something about over sharing, or her husband may be a part of the process.
Who Knows.
May be talking to you let her see what her life and future is like compared to yours and she didn't like that.
Who Knows?
May be your life, family, friends, happiness, completeness shone a light on her life and she didn't like her reality.
Who Knows.
May be her husband didn't like her having a friend.
May be he didn't want her seeing a 'Good Life" as a comparison to her life because he didn't want her realising how bad her life was.
Who Knows.
May be your kindness was too much for her. May be looking who you are and how people value you didn't sit well with who she thinks she is and how she is treated.
Who Knows.
There are a lot of Who Know's here.
A lot of You may never know in situations like this.
But what you do know now is;
1)You are fairly sure you dodged a bullet.
2) You consider yourself a kind person - you probably are or you wouldn't be hurt and confused by this situation.
3) You are a person who cares, listens and gives time and attention to others.
4) You don't need her in your life (or anyone like her or any drama in your life to make your life worthwhile)
5) You have family and friends in your life that you value and who value you.
I'd say you have a lot more answers to your question and understanding about the situation than you did before you posted?