Diva cup

I got the diva cup a while ago. I tried to get it in me, but it kept on popping open. I tried so many times, but I ended up giving up and switching back to tampons. Now I really want to try it to make it work. I hate having to buy so many tampons, and I hate having to ask my dad for money for them because I'm just awkward. I was curious of you input on them. I know when I look it up I'll get all the positives of it and how great they are, but I want to know the good and the bad of them. And how in the hell do you get them in!?!?!