Very sensitive to certain issues.?

After my first panic attack, I've since been very paranoid and fearful about dying or falling into a really deep depression. And I have had many more panic attacks since the first one. When i reflect on what actually cause them, then are often related. For eg, today my teacher was talking about the immune system and how people with long-term depression would lead to their immune system's eventual breakdown. I was so scared when i heard that ( because I have been in quite a long depression previously and I still am in one), then, i started to feel like i can't breathe properly and my heartbeat was racing! As seen, I'm very sensitive to these questions related to my illness. Is there a name for this disorder of mine? and how can i prevent these issues from affecting me negatively?

Try listening to classical music daily in the evening. You could also play ragtime music sometimes. They are highly structured and relaxing, and help to settle the mind and body.
Be sure to get enough sleep each night, especially before spending the day away from home.
Start a journal. Write about your experiences, what you were doing, what triggered them, what time of day, and analyze them putting your results after each. Re-read all of them at the beginning of each month, and refer back for details whenever you want to.
Do research on the things that upset you. Having a complete understanding of a scary thing takes away its power in your mind.
Usually, this kind of thing passes with time and learning. But you might also find a therapist can guide you through it more quickly.

You already got the names, Depresson and generalized Anxiety Disorder. They often go hand in hand. Aside from meds, do yourself a favor and get some therapy. In the meantime, take your vitamines and live a healthy lifestyle.