We all loose it every now and then so dont beat yourself up on that point.
In this particular instance you are giving out mixed message threats and demands that just will create more defensive responses and set everything back further.
You said you were not going to tolerate this hostility. How? What are you going to do about it as a thought out planned reaction? Throwing a threat back just fuels it.
Think about these quotes
I'm not going to tolerate this hostility anymore
my love for you is unconditional
I am going to walk out of your life
swear on our sons life
you that pushed me away
You're making a big mistake
pwBPD hear in edited highlights this likely what she heard. You have all sorts of contradictions, invalidations blaming,threats and embellishments happening. Only reaction you will get from a pwBPD to this is to fight back, and prove she is not making a mistake and indeed strengthen her resolve to make it your fault.
If you have your goals and boundaries more firmly established ahead of these crisis times you are less likely just to blurt out things like this.