Anxiety with intimacy

I very seldom open up to the internet as I know how cruel or wrong they can be but, I’m 14, I’ve been in a relationship with someone for a month. One day, nothing was wrong previously, a switch was flipped and I suddenly had intense anxiety when I was around him. I fought it but I couldn’t for long and I cut it off with him two days ago, I told him whenever I was ready I would come back to him. I don’t understand why this happened or how to manage it but the stress is getting to me and it’s caused me to go into a depressive state. My past relationships haven’t very fun either, both being toxic. I don’t know what to do but I really need to label this feeling as something before I lose my mind. I have no problem being sexual with him but the pure thought of being intimate with him brings me immense anxiety. I don’t know if I love him because I feel so disconnected from my emotions. What is this feeling called and how do I figure out how to reconstruct the relationship.