One thing, for me, that makes me think of borderline personality disorder is not having any specific thing to point to for some of the abrupt mood shifts and feelings. If you are constantly hypervigilant about relationships with the opposite sex (as opposed to ALL relationships) that shows a consistency that I don't feel around people suffering from BPD? And your feeling of not having things severely; everyone gets "sad" for a few days and loses interest in life, etc. but that doesn't make them clinically depressed; I think everyone gets some feelings of most mental illnesses but not to the "degree"/extent or length of time that people suffering from that illness do. Everyone changes their mind but not as abruptly or intensely as someone suffering from BPD can?