I would have to agree that talk therapy is VERY important in overcoming these issues and wholeheartedly agree that you should educate yourself before you try any 'natural' remedy. Of course, Paxiled or I are not qualified to determine if you in fact needed medication for the past 10 years, so we really can't tell you if you 'probably, probably didn't' need it. These are very personal decisions and as long as you coordinate with your therapist and doctor, I believe you are doing the right thing.
You'd have to taper slowly off the Celexa first, as St. John's Wort shouldn't be used along with an ssri. And as with medication, nobody can tell you if St. John's Wort will work or not. It also doesn't really address anxiety unless the anxiety is caused by the depression. What you would want to do is combine the St. John's Wort with 5htp and other remedies. Essentially, natural medicine doesn't treat symptoms, as does allopathic medicine, it attempts to strengthen what is weak in the body so as to heal it. It aims to treat, not mitigate. Now, many people do use it to mitigate, but that isn't how it's used by experts. You might want to consult a holistic nutritionist or naturopath to set up a program for yourself, and if your problem was mild, you probably didn't need medication anyway, therapy would have been your best bet. I hope you're doing therapy, as it would be an essential part of both natural treatment and allopathic treatment. Good luck.
I have not personally taken it before, but some people says it helps them while others don't have very much to say about it. Remember, just because it is 'natural,' you can take too much and it can interact with many things. Just ensure you understand what you are taking. Have you talked to your doctor or therapist about this?