Menstrual Cup Help!

So, I have a diva cup and I really really want to use it because I hate tampons and pads, but I can't ever seem to do it right! I know how to put it in, but every time I try, it opens up too early and it really really hurts the opening of my vagina. I thought that it would be easier after I lost my virginity (I know vaginas don't loosen up or anything after sex) but it was exactly the same. Do you ladies recommend any techniques? or do you think I should get a different cup? if so, what kind? Thanks in advance!