To me that does not sound like BPD. that sounds more like rapid mood swings form bi polar. like these other two people have said only a doc can diagnose a mood or personality disorder.
BPD has many characteristics that you would have to fall under. a few are frequent attempts at suicide, self harming behavior, risky behavior, intense extreme emotions, all or nothing thinking and the list goes on. BPD is very hard to explain I still have trouble explaining to people what it is when they ask. because its not something simple like oh I have a chemical imbalance in my brain.
well I hope you find answer on to what you have been experiencing good luck to you.