My first time trying intercourse

I don't know what happened i felt ready I've been with this guy for 3 years (I'm 20 he's 22) but when it came down to it it hurt me so bad when he would just try to get his penis in, and not 5 minutes after I had an awful panic attack I almost fainted. Is this something normal that this happened and I couldn't do it? we had talked about this many times and we both decided was the time and we could do it but I just physically wasn't able to... Any recommendations as to what I could do so I can take this big step and enjoy it?