Hi,
I posted a thread about this yesterday because I was starting to get worried about my painful, lumpy breasts - I'm glad I'm not the only one!
I found a couple of websites where they had done trials and actually found that wearing a bra is not a good idea, apparently it's because of the heat caused by wearing one. Try looser clothing like cami's. I know its painful when they are loose but I'm going to give it a go
Also it suggests really cutting out the caffeine (coffee, tea, cola, chocolate). If you find it hard to do this all the time, why not try a couple of weeks before your period? Other suggestions are Vitamin A, C and E supplements.
Something else I read stated that if you don't have more than 3 bowel movements a week this can also be a factor in causing the cysts.
I hope this helps.