Sex with guys with big dicks

Me and this guy I’ve been talking to for months now had sex for the first time a little while ago but when he put it it started to hurt, (his dick is pretty big) which is what I think could be the problem. I have had sex many times before and this time it was like a hurt that I didn’t want him to keep going so I was wondering if this ever happened to you guys.you know when you say you can feel him in your guts like I literally felt him all in there. Will it get better?will my body get used to it? If he keeps going will it eventually feel good?....like I’m so horny and I want to have sex with him but then when we try it hurts