The best plan under these circumstances is for you to see a medical doctor regularly so that he or she can keep an eye on your health. And, of course, I am not a doctor and so I am not giving medical advice. I would certainly consult with a doctor in regard to any steps that you take in regard to your health.
However, if you are in a situation where you do not have insurance, or you are between appointments and cannot see your doctor, or you are in Court and something comes up and you need an immediate solution to your problem so you can make it through an afternoon hearing, I have a few suggestions for over the counter remedies which you can purchase at your local pharmacy to tide you over.
Again, I am not a doctor, so if you have any reason to believe what you are going through is life threatening or could damage your health, you should immediately contact your physician.
I also believe in adjusting your cognitive response to these kinds of pressures, and so I would highly recommend cognitive therapy to work on your attitude towards your situation so that you can develop ways of responding to your divorce that move your forward rather than bring you down.
If you are interested in taking St. John's Wort for your depression, I'd definitely look it up online for any side effects that could be a problem and to determine how much you should take. And, of course, consult with your doctor to be sure it is an appropriate remedy and that you are taking it the way it should be.