You're not ranting. What you are stating makes sense, and it makes sense that for you, a diagnosis may provide answers. A psychological evaluation is a series of standardized testing administered by a psychologist and may help give answers to if it's a mood disorder, personality disorder, organic problem, etc. It may also give your therapist some direction as to what they're up against. I always refer for psychological evaluations if I am unsure about where a client may fall in diagnostic criteria. Perhaps ask your therapist for a referral? They are expensive, so hopefully insurance will cover this. But if you get a good psychologist they can do a really, really good job gathering ALL the information needed to administer the test and get you some of the answers.