<human>: I've been dating this girl for the last couple of months: we like each other and it's all been pretty much good.

She told me she doesn't really like PIV, because she doesn't feel anything while doing that, but that since I really like it she would be okay doing it.  

Over the last couple weeks, she brought up the idea of dirty talk, which I'm not really a fan of but hey, if that's what gets her, why not?

My problem came up a couple nights ago. She told me she likes it rough and she wants me to "use her". That didn't feel right and I was kinda turned off by that, but I shrugged it off as me being a little vanilla under the sheets. I tried to be rough, but I am afraid of hurting her (I'm pretty big and tall and she's definitely smaller than me).

I don't know what to do: on one hand, I REALLY want to please her while doing PIV (even if I obviously go down on her before, because hey, otherwise it's not really fair, right?); on the other hand, I feel awkward talking dirty and going rough on her, probably because 1) I don't know how to do that and 2) I've never did it before.

Am I overthinking it? I don't really know what to do, honestly.

Can you summarize the given text in a few sentences?
<bot>: The girl I'm dating wants dirty talk and rough sex, but I feel awkward doing that. What should I do? Any tips?