Kaplods you sound a lot like a friend of mine who had all those symptoms. She ended up having a laparoscopy to have lumps from her fallopian tubes removed and she was greatly improved after that. Have you ever been to a gynaecologist to have that checked out?
Whacky weight gain in a week will just be water loss/gain. What's to worry about. Of course if you are eating a lot then it will be more than just water.