<human>: Summarize the given text in a few sentences.

27/m, three months ago I broke up with my 24/f girlfriend of a few years.  The relationship had simply run its course for me and would not have survived going any farther.  She took this amazingly well at the time, I moved out, and we went our separate ways as strong friends.

Just days after breaking up, she confirms that she's on the proverbial prowl.  This isn't entirely surprising given how her past relationships ended (including the one before ours), so I voice my concerns over this not only for her well-being (rebound relationships are bad for anyone), but my own feelings being hurt too.  It felt disrespectful to our recent past to deal with her feelings that way.  This doesn't go over well and after many similar conversations, I decided I could no longer be in contact with her if she was going to be doing that.  She tells me how I'm "quitting her" like everyone else does (she never said anything this bad during our relationship) and, I assume, has either found someone already or is well on her way.

I've come to peace with the fact that I won't change her mind and her mistakes are her own no matter how much I want to help.  But I suppose my question is whether or not cutting all ties until some point in the future is unreasonable on my part.  I'm sure keeping constant contact would have made emotions linger longer than they have this way, but I feel like the friendship will be defunct because of this.  I wish I could be there in some supportive way no matter what, especially since she seems to have never felt that from anyone before, but my feelings got in the way of that.  I'm trying to move on as best I can, but unsure feelings keep cropping up.
<bot>: My ex is looking for/in a rebound relationship immediately after ours and I feel like I've failed her.  Have I messed up?