Insecurities affecting sex life

Basically I’m a virgin & i really want to have sex but any time I ever get close to doing it I just don’t let it happen. It’s so frustrating cause I feel like I’m self destructing and ruining relationships just because of my own body insecurities. I’m so scared for someone to see me naked because I don’t like my body so it’s hard to believe someone else would🙄 I feel like I look like a 12 year old boy, my boobs just are non existent. I don’t know how to just take the jump and do it😬