It has been my experience that bipolar is hereditary. As far as what causes bipolar, there are millions of web-sites, this one included, that will give you a clear picture. Google it and read away. A lot of people have some anxiety and panic attacks in conjunction with the various aspects of depresion. Make sure you tell your doctor everything you're thinking and feeling so that you can get the right course of treatment.

What you can expect treatment wise depends on both the physician and how active a role you play in the decision making. It's important not to allow them to control you, but to work with them. Do not be afraid to be vocal, speak your mind, or say what you truly feel. If you don't agree with something, say so. I can understand being terrified, but there's really nothing to be terrified about. You're getting help, which is a fabulous start. This is something you suffer from, it is not your fault you have it. You will have good days and you'll have bad days. The right medication and combination of doctor/therapy should help you work through things so that you can go back to living a life that you are comfortable with. I wish you the very best life has to offer.