Hi, sounds like they turned away from you, if not physically then emotionally. They just made themselves out of reach (whether it was intentional or down to their circumstances). And maybe your unconditional love wasn't something they were able to feel or accept in their lives (and that doesn't mean because it was you) so however much you loved/were there for them that still wasn't going to give them what they really needed/wanted (whatever that may be) and was only going to tear you apart.
Something tells me that a relationship (a "proper" relationship) wasn't really something they needed anyway to help them with their problems, do you think??
In fact all the things that come along with a relationship like trust, commitment....might have even made things hard for them alongside everything else, maybe??
And really you tried your best, didn't you? You gave it your all. Sometimes that's all we can do.
And it's not that it wasn't up to you to save them really, it's more a matter of someone needing to save themselves. Of course they can need someone else to empower them to do that, but if they simply aren't ready or not in a place to be helped then whatever someone else does isn't going to make that much of a difference.
Now I dare say you gave them some "tools" to be doing that during your relationship, and maybe there's a chance at some point they'll look back and use some of those "tools" you gave them to try to help themselves as well. But there's only so much you can do.
And the "what if", you know it was possibly headed to being even worse if it carried on.
So, yes, I'd would definitely say you did the right thing!! And really admire your strength even though I know it must be hurting right now.
And no arguing with me!! but you have got great perception, sensitivity and insight so maybe trust in that a little more. Underneath (deep down) you know you needed to let go and it was the right thing to do, so just try to have a little more faith in that (I really know that can be hard but....).
Alison