Pain inserting anything in my vagina

Hey so I’m 15 and have had my period since I was 12. For someone my age I surprisingly know a lot about vaginas (I want to be a gynecologist when I’m older.) I have never been able to comfortably insert anything inside my vagina without pretty bad pain. There’s only been a few (less than 10) occasions in which I’ve been able to use a tampon. The tampons have always been the smallest size I can find but it always seems/feels like they aren’t in correctly. I’ve also had someone try to finger me and tried to finger myself, but even going barely in hurts. The only thing I have found that could be the cause is vaginismus. I guess I’m looking for any sort of help/comfort/advice. I know I should probably talk to my parents/doctor about this, but I’m honestly ashamed. Please help :(