What should i do about my l itchiness?

well ever since i started having my is itchy all the time, also after i it gets itchy too, its really annoying and washing it doesnt help at all, i even tell my boyfriend not to touch me beacuse of the fact that it gets to itchy.. what causes thiss?? and how do i get rid of it?? what medicine shoud i take or is there any lotion that cures itt????????????????