First things first: As surely as you can state that you are a normal man with a normal anatomy, I want you to remember that your partner is normal with a normal anatomy. Everyone's body is different and while hers may be different than others you've dealt with, it doesn't make her abnormal.
Let's talk about a couple of surefire ways to NOT satisfy a partner:
OK, moving on. I see a lot of you in this question: your dick size, how you can't get it in, how you want to be told what to do. All I know about your partner, on the other hand, is that she is shy and you have emailed measurements of her genitals to a stranger. How does she feel about her mons? Right now I'm guessing she's not feeling great about it, but how did she feel before all this obsessing started? What does she like in bed? Has she had this issue before? Does she even consider this an issue? Is she unsatisfied (apart from the body shaming?)?
I suggest you get your hands on a book called "Curvy Girl Sex" by Elle Chase. It combines theory and tons of practical advice (including positions and toy recommendations, both of which you may find helpful). I think there's lots in there for both of you. Start with the body image stuff. I think you may both need it.