The key is to take things one at a time. I had a panic attack when I tried to talk at a town meeting about something - I am very bad in front of strangers. I felt like I was going to collapse.
Michelle - don't think about life as "I must do X because in the past I planned to do X". People change. Paths change. Something that was perfect for you 5 years ago may be not right for you now. Sit down and decide NOW what would make you very happy. Yes, it might involve a new career - but TONS of people change careers completely. Lots of people hit retirement and do something diametrically different and are so happy!
We should always do what makes us very happy. Pursue your dreams