First time tips

Amy
So i'm almost 18 and i've finally decided to have sex for the first time. The reason that i have been putting this off for so long is that i'm sooo scared of the pain. I've tried so many times putting in just one finger in me while masturbating and sometimes it's okay but sometimes it's HELL no. I'm not pain-tolerant and i've always be thinking that i could not handle the pain and everytime when my boyfriend asks me if i'm ready i think i finally am but when we get to the sexy time i just change my mind. We've been together since 3 years and i think its time already to overcome my fear so please any advice would be helpful 😔