Is there any way I can make my vagina looser?

I know that sounds crazy since usually girls want to know how to make it tighter, but I'm already pretty tight naturally. I recently started dating a black guy. He's the first black guy I ever dated. I always heard the stereotypes about them being well endowed and I don't know if it's always true but in this case it definitely is. We tried to have sex for the first time last night but we couldn't because he couldn't even get it inside me! Not only is it bigger then any of the guys I've ever been with but it's even bigger then some of the ones I've seen in pornos. To give you an idea, he's 6'4 230 lbs. (he used to play college football) and I'm only 5'4 115 lbs. so he's basically twice my size. And his penis is the size and thickness of my forearm!!! I've never had anything that big inside me before so I'm pretty sure it's going to be uncomfortable at first no matter what, but I really want to try it, at least once. Like I said we tried and we couldn't even get it inside, like not even the head. We had tons of lube and we tried for like 20 minutes trying different positions and stuff but I still couldn't get it to go in. I haven't had sex in a while so I know that's part of the problem but I do masturbate with a dildo regularly. Obviously the first step would be to buy a bigger dildo to practice with, but what else can I do in the meantime? I'm afraid that if we can't have sex then he might break up with me, and I really want to know what it feels like to do it with him at least once since I'll probably never meet anyone with that size 'equipment' again, lol. Kind of like a bucket list, I want to do it with a guy whose hung like a porn star at least once before I get married and settle down.