AIO for being anxious about starting my first relationship?

I'm 15, about to turn 16 and recently have started flirting with a boy. We know we like each other and we have great conversation before that was established. I feel really really anxious after he confessed that he liked me. I don't know why, I've liked him for a couple months and don't know why I'm feeling so anxious about it. I do have some trauma around intimacy and stuff like that. I told him that I wanted to keep things casual and be better friends before anything happens, and he was very very accepting of it. There is absolutely nothing that he has done to make me feel uncomfortable, and when he said something that I took to mean differently and made me really uncomfortable (not his fault, just my trauma brain lol) He made me feel very comfortable. This post may make absolutely no sense, but this is my first relationship and I have dealt with severe anxiety for the majority of my life, so I can't tell if this is just normal butterflies. Also, the age gap makes me slightly nervous. He is a senior and I am a sophomore, and as I previously mentioned I have some trauma around intimacy, but I truly don't think he would take advantage of the age gap. Please tell me if this is normal since I have zero experience, and what you would do in my position. Thank you for reading this far! Have an amazing day!