Size ... awkward

Okay so I need some .. advice ? Lol So I just started having sex with my boyfriend. He wasn't my first so I wasn't a virgin, but he is a lot bigger than the other guys I've been with. I'm always really turned on and lubricated when we do it so I don't think that's the problem. After we do it or even about 20 minutes in I start to get really sore. Like we did it a few times this weekend and I'm just really swollen down there now and almost feel like I'm getting a yeast infection. We've been having sex for 1 week now so I'm not sure if I'll get "used to" his size or if there's something I can do to help this ?