You don't have to be embarrassed for asking about your female body, it's a pretty complicated system. It's most likely Vaginismus, which is when the muscle walls tighten up making any form of penetration painful or feel like its blocked. It's mostly a psychological thing than it is physical. And irregulat periods are related to your estrogen and progesterone levels, so the chances of these two conditions having a link is unlikely. And no, you're not going to die it's very common. You can Google more on the matter but if you're too worried you can ask a gynecologist 💓