Hi, I'd like to help you with your question,
It sounds like your boyfriend could have a personality disorder. Without a full evaluation by a therapist it is hard to tell. Many people have symptoms of personality disorders but do not meet the criteria for a diagnosis. If you boyfriend has five out of the nine symptoms of Borderline, however, than he may have the disorder.
There is help for people with personality disorders. Therapy can help reduce or eliminate the symptoms. The key is whether or not the person has enough insight to see that they have a problem and it is affecting other people. If not, then therapy will not help.
Talk to your boyfriend about how his behavior is affecting your relationship. Let him know you want him to consider getting help. Offer to go with him if you think that would encourage him to go. If he still refuses, then you may have to consider a separation. Sometimes separating helps the other person see how serious the effects of their behavior are on the relationship.
Here are some resources to help you:
Should I Stay or Should I Go?: A Guide to Knowing if Your Relationship Can--and Should--be Saved-Lundy Bancroft
I hope this has helped you,