Most do this to be honest, it's just a natural reaction and part of the social norm, so don't beat yourself up about this. Ideally, with people you can talk to, try to stop saying "but....".

However, even then, if you say it, there's nothing stopping you from going back and talking to them. I'd suggest maybe speaking to your friend. Don't even wait to be asked, but instead ask if she's ok to speak to and just let it out. We have this habit of keeping things in and it's simply not healthy.