Virgin looking for advice

Okay ,so I really wanna have sex with my boyfriend, I am a virgin. He is the the 1st guy that I have been craving him so bad especially now that I haven’t seen him as much as before ( every day) . We have talked about it and everything but as the day gets closer I am so nervous. I have a low pain tolerance and when am scared of pain and I freak out when it comes to pain . How do I calm myself , because I know I am going to freak out (from past experience) . Is there like something that helps you calm your nerves .