I used to have those kind of runaway thoughts around my periods...like I was wired and could not settle down. Mine was helped with progesterone cream.
I am doing meditation and I don't try to focus; more like I am easy on myself and just "watch" my thoughts like I am an observer. I think when you try too hard it makes it harder to ever calm down. I think if I just practice regularly it will become more natural.
Also if you could afford a massage, I have found that a massage quiets the body, and when the body is quiet the mind becomes calm too. I have not had too many of these but I do find that they have been great for helping me feel calm mentally. I don't like the overly aggressive deep tissue ones as they are not relaxing but I went to a woman once who did healing touch I think it was called and it was wonderful.
Hope you feel better soon.