Hi Angelique, welcome to the board.
Well, to answer your first question, it is you, yes, but it is also a medical illness.
... If you have a monthly pattern of symptoms, which your post suggests you do, then it could be PMDD. However, it is important to have yourself properly diagnosed by a knowledgeable doctor.
Many underlying medical conditions exist which can either cause or exacerbate premenstrual symptoms (or PMDD), they can also cause clinical depressions. Chronic low-grade and long-term stress is the major culprit, but I would suggest you have a thorough medical exam (and a 2nd opinion) to make sure that there are no underlying medical illnesses. Your age also plays a role here, as it could be peri-menopause if you're over 35 years old.
Also, you say you have been on anti-depressants for a long time? Clinical depressions are known culprits in making premenstrual symptoms worse, i.e. PMDD in the worst instances. If the underlying problems are not resolved, then it would be of little use to try and treat the PMDD as a single entity.
There is a lot you can do to help minimize the effects and symptoms of PMDD, I suggest you read the information here on this site, as well as my main web site (link "PMS & PMDD Information Site").
All the best,
Anthea
(PS: I'm from South Africa too!
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