trying my best, need help

Hey y'all,

I've been in a relationship with my partner for about 3 years, and things have been good. We have had a very mild dom/sub relationship for a little while, but recently they asked me very clearly to take domming more seriously, because it's very important to their enjoyment.

The biggest hurdles I'm facing at the moment are that I find domming to be embarrassing, I never know what to say or do, and that I don't enjoy hurting my partner.

I have tried watching videos of other people domming to learn and get ideas of what to say but every time I get super embarrassed and I cringe at it. I feel similarly in the moment, like intellectually I understand that my partner enjoys it, but I can't help feeling like a dweeb, which takes me out of it.

The other thing is a little harder I think. My partner very explicitly enjoys being hit and in their words "beat up", but they are much smaller than I am, and I'm afraid of seriously hurting them. I want to learn to enjoy it, because it's been a cornerstone of their sex life for most of their sex life before our relationship, but I don't know how to get there. (for reference i am 6'1 27M and sling concrete bags around for work, they are a 5'2 with a desk job)

I am going to start by reading The New Topping Book, I've been told that is a good place to start, but I was hoping y'all might have some more specific recs for the issues listed above.

Ty for your time :)