What is wrong??

I am 15 years old and I was masturbating and I felt something hard in my vagina, I went in front of the mirror and when I "opened" my vagina I saw that I had white things in between the big and little lips.. I tried to remove it and it was hurting when I  finally removed one thing, it was hard and had the shape of an almond. Can you help me?? what is it??