Welcome to the forum.
I'm so sorry you have lost your friend and feel you have been rejected. (Or perceive you have been rejected, sometimes it is possible to perceive we are rejected, when this might not be actually the case). Either way we feel the same way and your post is clear on this front.
Loosing a very close friend and the feeling of being rejected (as you know), particularly when there are other negative things going on is emotionally extremely painful. Going over and over everything tends to be emotionally draining too, she did this, wish I'd said that, wish I'd not said that!, if only this, why did that happen ?, did she have to do that ?, why did she do that, was it on purpose, ... it goes on and on. Try to give your mind a rest, using your favorite remedy (if there even is one).
Whether your friend is a narcissist is impossible to say, people change over time and who knows what might have been going on with your friend or what they were going through or why they did what they did. Either way we can't turn the clock back.
Try to be very easy on yourself and take time to recover doing the things that you enjoy most, (if that's even possible right now). As we all know in time these things fade and we do recover and become slightly wiser (hopefully!) people in the future.
Sorry if this did not help much or at all, what you are going through, loss and rejection are really painful things that no amount of words from someone else can heal (I wish I could) however well intended!