You’ve done a good job of describing your struggles. I m happy to read that you have found some solutions, and that you are feeling mostly stable and in control of yourself. The world of mental health treatment is a mess right now and psychiatry is kind of floundering. They have tied themselves to a medical/pharmaceutical model, yet the underlying causes are much more complex than that.
I have no idea of what was going on with you during adolescence, and why you felt so confused. Perhaps a therapist would have been better than a psych hospital, but I’m biased, having been a therapist for forty years. However, whoever it is that treats you should listen to you before they do anything. The doctor who first diagnosed you based his/her opinion on what was the trend at the time. Everyone who was visibly upset was bipolar. No one quite knows what bipolar means, and there are probably many different variations.
The origin of psychological and emotional difficulties are very complex. They involve social, biological, genetic and other environmental factors. When one of things gets out of balance it affects everything else. The things that upset you are probably both internal and external.
I hope you are learning to see what affects your moods, and to anticipate, as best you can, what helps you. If the drugs help then you are fortunate. Effexor has been helpful to many people, but it has many side-effects, and be aware that most people have a very difficult time if they want to stop taking it.
Hang in there. Continue to trust yourself and your judgement.