A frontal lobe tumor could potentially account for the issues that you describe. I guess that if the psychological issues predated the tumor, you could be dealing with a pre-existing personality disorder -- maybe and maybe not. It's also quite possible that you have no "mental" disorder at all and that you are just experiencing the difficulties of normal life and relationships. LIfe isn't necessarily all that easy, for most people. If you really need to know for sure if you have bpd, the best way to find out is to be evaluated by a psychiatrist or psychotherapist. If you are being followed by a neurologist for your brain tumor, you could ask him or her if that's a good idea. Sorry for your troubles.