2 parts

So the wife is really into the rough sex. She has non-consent fantasies, and on more than one occasion asked me to be rougher. Pulling her hair, choking her, hitting (I’ve only smacked her ass, don’t know if she wants more)

I worry that I’m not doing enough to satisfy this kink for her and i worry about overdoing it as I’m not a small guy. And if I caused her any real pain I would feel awful.

Side note, she also tells me to do what I want, and when I try to talk to her after she just reiterates to do what I want and this circular conversation doesn’t end.

TL:DR She wants it more rough, I’m a chicken shit worried about hurting her. How do I get over it?