Your girl could push out a baby if she wanted to; your penis WILL fit.

What did you do wrong? Well, for one thing, it doesn't sound like you actually looked for her vagina at all. Do you even know what her vulva looks like? Have you stuck your fingers inside of her? Ever given her oral sex? If you say no to any of the above, then you're not ready for vaginal sex. I do applaud you for the condom, but if you don't know where her vagina is...

My suggestion for next time: Buy some lube or have lubed condoms. Once it's on, feel around her with your fingers, and find her vagina. Slip your fingers inside, feel how you can stretch it out - if she's turned on. It'll help loads if you stimulate her clitoris first. She will become looser and more lubricated and more receptive to you. You can be as hard or as small as you want; if she's not turned on, you can't fit a pencil in there.

You need to remember that sex is about HER too. "She gave me oral like normal..." Well, what have you done for her? Sounds like you just want to stick it in her and hump to your own satisfaction without any care for her pleasure. Did you know most women can't orgasm from vaginal sex?

I assume you're both virgins. I'd like to add on that note that just because she's a virgin doesn't mean she has to bleed her first time, and NO it doesn't have to hurt. If you are hurting her, you're most likely doing something wrong.

How about you explore HER body with your mouth, and pleasure HER before trying to stick your penis in?