I (f) am too sore to have sex after the first time with boyfriend.

My boyfriend is in town for the weekend (we are long distance). We tried to have sex the first time on Thursday afternoon. It didn't really work, so we went out and I drank. We came back and sex wasn't bad. It went in, and that was that. We woke up, had sex again, and it didn't hurt. We tried to have sex the next day (Saturday) and today (Sunday), but it just hurts. It hurts way more than it did the first time. I'm kind of petite and my boyfriend's dick is wide. We have lube and he does foreplay with me a little before hand. It feels like he's shoving a watermelon down there and we can only get the tip in.

Any help?

TL;DR: Lost virginity. A day or two later can't have sex. Hurts too much. Boyfriend's dick is wide. I'm petite and tight.