
you might have to do some gentle work with your fingers also. i don’t mean that in a perverted way, but your hymen will need to stretch a little bit. it’s not something that actually “breaks”, it’s more like a donut shape that just has to be opened up. but seriously, even as someone with experience that way, i have to use lube every time to put my disc in and don’t tense up, just breathe and try to relax. might have to lie down, maybe throw a towel on the floor of your bathroom and try that way
it’s not supposed to really hurt like that, but it is common to have some discomfort. a cup honestly might be too big for you. i use a disc, you fold it to be inserted. it ends up being about the size of a light days tampon just flatter. if you can’t get it in and you need something that’s not a pad asap, maybe try tampons first. good luck!!
if you’re determined to get the cup in though, just go super slow and use a lot of lube. the sharp pain is a sign of the hymen tearing, which isn’t the end of the world and is what a lot of people experience their first time having penetrative sex, but you may not want to put yourself through that stress and pain.