Hi Ash, welcome to the board.
There are a number of things you can do to alleviate your symptoms (you will find all the advice you need in this regard by reading through the older posts).
However, I would highly recommend you go and see a gyneacologist asap as your physical symptoms do seem quite severe and could be an indication for a reproductive disorder (pco's, endometriosis, etc. etc.) Only a qualified gyno can give you an accurate diagnosis. If you do have a disorder of some sort and it is treated correctly, you may well find your pms symptoms lessening, or even disappearing altogether.
So your first step is really to go and see the doc and get a proper physical examination and check-up to make sure that there isn't anything else going on there exacerbating symptoms premenstrually.
All the best, and let us know how it goes.
Anthea