pain deep in vagina when aroused??

So whenever me and my SO are making out or anything along those lines I get this deep sharp pain in my vagina and around my Labia and such and it goes away once we start to have sex but the pain is so bad we don't usually make it to that stage and I don't know where it's coming from, I googled it and all the girls said that it happened during or after pregnancy but none of the doctors could diagnose it? but I'm 18 and never been pregnant, I've recently been tested just in case but nothing came back,  We don't have sex very often because it hurts so bad when we try and I don't know what to do now? Does anyone else experience this and k kw maybe what it could be?