Ready but not ready I guess?

Hi everybody. I have a situation that’s been bothering me. I recently started back talking to an old guy friend that I kinda have a crush on. Last night we were hanging out at his place just chilling and getting to know each other more when the topic of sex came up. I’m a virgin and I’ve never had a bf and last night he asked if I wanted to have sex with him. I told him that I wanted to but I wanted it to happen naturally and when he openly asked I started to freak a little. I really really want to because I trust him and he confirmed that he liked me too. I honestly don’t know what to do. Should we talk about it more? Has this happened to anybody else? Like I said, I want to because I trust him, but what did that mini freak out mean? Please give me advise.