I lost my virginity at age 10.
Is that really true? Can you talk to me about it?
Even today I feel so much pain whenever I see her.
Of course it is not good to lose one's virginity at such a young age, but that has already happened.  It is understandable that you would still have feelings for someone who meant so much to you when you were younger, but it shouldn't be causing you pain.  Maybe you can talk to someone about your memories, and they can help you to move on.
It's just hard for me. My friend tricked me thinking I was getting a good birthday present and that's how it happened.
That sounds like a very traumatic experience, I'm glad you go forward with it now in order to heal. While you can't change the past, you can acknowledge it and make it a part of yourself in order to get on with your life properly.