How can I realise if I am setting healthy boundaries, or actually overreacting?

In the past few months, a friend of mine has disappointed and hurt me on a few occasions. She would apologise though, we would talk about it, and I was fine with it. We all make mistakes and as long as someone apologises to me, and learns from their mistakes, I am ok.

Now it has happened again and it feels like it has simply become too much for me to accept...

Something happened to me last week, and it keeps bothering me. So five days ago I shared this with her without going into details and asked her to let me know when she had a few minutes so we could have a chat. I understand she has lots of things going on in her life as everyone, and I don't mind waiting. Since then we have talked briefly a few times. She would call me on her way to work to vent about her husband/her children/her job, she would go on and on and I would listen and support her, and then she would say thanks for listening, I'll go now. She would also text very often, always to only talk about her and how her days were difficult and asking for advise. She never asked me about what had happened to me. I asked her again a couple of times if she had some time for me, no answer.

After five days, I told her I am upset now. She apologised and said she wants to listen to me, that she didn't do it on purpose, that she cares and all that stuff. But I can't now. It just doesn't feel right. I told her I was grateful for her apologies, but I don't feel like talking right now. Perhaps in a few days I will. I asked her to please not write to me, I need some time on my own. And in her reply... she wrote, 'well if you don't want to talk when I am available I don't see how we can do this. Bye'.

I don't like that reply. She is entitled to be upset but, well, that's not a nice way to reply. I find it passive aggressive. It feels as if I should be grateful for her being available now, and just forget what happened. But friendship to me means something different. It means being available even when you are not available, in a way. You don't have 5 minutes, but you still find them. You go the extra mile. Not always, of course. But for emergencies, yes.

Besides, if I don't feel like talking now I can't force myself, can I?

I know I could have made my needs maybe more clear. Or simply call and 'force' her to listen to me. But I am not like that.

I can't figure out whether my BPD is blowing things out of proportion, or if I am actually setting healthy boundaries. I would appreciate any insight you may have.