So what your saying is that I love him at this moment and he ceased to love me a 11 am on March 19th?
Not quite that literally, but kinda actually. Acting loving in the absence of emotion is something Scott Peck discusses in The Road Less Traveled. Since pwBPD are emotionally driven and intimate attachments are triggers - your quote is somewhat true - just keep in mind as quickly as it can swing to this, it can swing back the other way as well.
At the end of the day - the kind of relationship you want, it doesn't sound like this person was really able to give you. It is painful to breakup, but - when someone shows you who they are... . we really should believe them.