i need some advice

so basically my bf is into some bdsm/dom stuff. i’m all for a bit of it but to be honest i prefer being in the domme role, but i never have been. does anyone have any suggestions on how to talk about it or introduce that sorta thing? because i’ve been struggling to “O” during sex and i think it may be because of the power dynamic we’re in rn, i prefer more of a 50:50 sorta thing. i dunno im not rly good at talking about this stuff but he’s never made me finish before and i don’t know if it’s just bcs of the way we’re going about sex atm. he’s down to try being more of a sub so i guess im just looking for how to bring it up and how to start off if we do it? anything is appreciated