I would try to focus the shocking aspect of it into making it feel more exciting than anxious, if such a perspective shift is possible for you. I've experienced shockingly easy results where a girl approached me, I got her number and had her over at my place very quickly the next day, not due to my great game or anything. Just dumb luck and the fact that she seemed pretty easy and horny. ANYWAY, the point is, I just went with it. Sat her on my bed and escalated. You'll find the weirdness of the situation becomes less and less important the more turned on you both get. That's not to say you shouldn't go as slow as you need to in order to feel comfortable, but ya know... Just get her over and kiss her or touch her or whatever. I ended up feeling my girl up, grinding my leg between her legs and putting her hand on my crotch (some classic, go to moves

)
Summary: get her over, chill out and go as slow as you need, but realize when you are both turned on you probably will only care about giving it to her.
Good luck.